The document analyzes theoretical models for predicting two-phase frictional pressure drop during condensation in mini channels. Experimental data from 454 tests with hydraulic diameters of 0.952-1.152 mm and refrigerants R290, R1234yf, R1234ze, R22, R32, R410A, R134a and R152a is compared to eight pressure drop models. The Kim and Mudawar (2019) model best predicts the experimental data with a mean relative deviation of -7.36% and mean absolute relative deviation of 12.21%. A new modified correlation is developed that improves on the Kim and Mudawar model with a mean relative deviation of 0.000165%
CFD Analysis for Heat Transfer Enhancement of a Corrugated Plate Heat Exchang...ijtsrd
The flow properties of heat transfer across such corrugated channels are very distinct from parallel plate channels. The primary flow direction is parallel to the waviness of the channel of the corrugated channel, although the local flow direction is still changed due to the waviness of the channel. By flow recirculation, separation and re attachment, the thermal boundary layer formed on its walls is regularly disrupted and the convective heat transfer coefficient is thus increased. In this work, in corrugated channels, the convective heat transfer and pressure drop characteristics of flow have been tested numerically. On channels of uniform heat flux and fixed corrugation over a Reynolds number spectrum, 10000 = Re = 30000, numerical research was conducted. The impacts of channel configuration, variation in Reynold’s number, and concentration variations of nanoparticles in base fluid on heat transfer are discussed. As opposed to the traditional corrugated channel, a major heat transfer gain was associated with the proposed corrugated channel. Based on the nanofluid concentration, Reynold number and channel configuration of the corrugated channel, the average Nusselt number increased by a factor of 2.2 up to 2.8 compared to that of the semi circular corrugated channel. Compared with the effect of channel configuration variation, triangular corrugated channel was the best Nusselt numbers, followed by the shape Semi circular Triangular , and Semi circular corrugated channel with the lowest results. Prof. Pushparaj Singh | Rishi Kesh Jha "CFD Analysis for Heat Transfer Enhancement of a Corrugated Plate Heat Exchanger using Different Corrugated Channel Configurations" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-6 , October 2020, URL: https://www.ijtsrd.com/papers/ijtsrd35706.pdf Paper Url: https://www.ijtsrd.com/engineering/mechanical-engineering/35706/cfd-analysis-for-heat-transfer-enhancement-of-a-corrugated-plate-heat-exchanger-using-different-corrugated-channel-configurations/prof-pushparaj-singh
A Review on “Investigation of Heat Transfer Enhancement of Flow over the dimp...IRJET Journal
This document reviews investigations into using triangular dimple shapes on the internal surface of a divergent duct to enhance heat transfer. A divergent duct promotes fluid mixing and reduces pressure drop compared to a cylindrical pipe. The addition of triangular dimples, which act as an extended surface, can further increase heat transfer by 40-50% over a plain divergent duct. Previous studies have found triangular dimple shapes provide the highest heat transfer enhancement compared to other surface shapes like cylinders or fins. The enhanced mixing in a divergent duct with internal triangular dimples can improve heat transfer for applications in industries like food processing and chemicals.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Analysis of Heat Generation in Double Pipe Heat Exchanger: An Experimental Ev...IRJET Journal
This document summarizes research on analyzing heat generation in a double pipe heat exchanger with an elliptical fin surface contact. An experiment was conducted to compare the heat transfer rate of an elliptical fin to other fin types (tube-tube, rectangular, annular, spiral rod). The results showed the elliptical fin had a higher heat transfer rate. The document reviews several other studies analyzing different fin geometries, heat transfer optimization techniques, and computational fluid dynamics simulations of heat exchangers. It provides background on analyzing heat exchangers using methods like logarithmic mean temperature difference and effectiveness-NTU and discusses prior work optimizing dimensions, materials, and flow conditions to improve heat transfer performance.
Review on Effect of Chevron Angle and Numerical Investigation of Dimensionles...IRJET Journal
The document reviews the effect of chevron angle and numerical investigation of dimensionless numbers in plate heat exchangers. It discusses previous research that has examined heat transfer coefficients and pressure drops at different chevron angles. The paper aims to design a plate heat exchanger using different chevron angles and evaluate heat transfer performance through simulation analysis of numbers like Nusselt, Reynolds, and Prandtl.
Experimental investigation of flow condensation heat transfer in rectangular ...IAEME Publication
This document summarizes an experimental investigation of flow condensation heat transfer in a rectangular minichannel. The study measured condensation heat transfer coefficients and pressure drops for steam condensing in a horizontal aluminum minichannel with a hydraulic diameter of 2mm, where water was used as the coolant. Results showed that the heat transfer coefficients and pressure drops increased with increasing mass flux and vapor quality, due to higher vapor shear forces and thinner liquid films. The experimental data was also compared to existing correlations from other studies on minichannel condensation heat transfer.
Design & optimization of LNG-CNG cylinder for optimum weightijsrd.com
In current automobile sector, the weight of the vehicle is too important to increase the efficiency of the vehicle. There are too many component or subassemblies are in the automobile vehicle. In this paper the weight of the HYDROGEN fuel tank is optimized by applying the composite material concept with the existing material of the fuel tank. Initially the dimensional calculation for the existing pressure vessel and compare with the existing cylinder and then the FEA ( Finite Element Analysis) applied on the cylinder and material optimize up to the stress reaching equivalent to the stress of the existing cylinder. After that the dimension of the cylinder are finalize. The analysis yields a weight reduction of fuel tank.
IRJET-Numerical Investigation of Heat Performance Enhancement for a Double-Pi...IRJET Journal
This document presents a numerical investigation of heat transfer enhancement in a double-pipe heat exchanger with continuous helical baffles in the annulus and either water or alumina nanofluid as the working fluid. The study varies baffle spacing, mass flow rate, and nanofluid concentration to analyze their effects on heat transfer rate, pressure drop, and thermal performance. Results show that adding helical baffles increases the fluid flow path and turbulence, enhancing heat transfer. Replacing water with nanofluid further improves heat transfer while also increasing pressure drop. Graphs comparing the different configurations are presented and agree with previous research findings. The goal is to optimize baffle design and nanofluid parameters to maximize heat transfer rate and performance for practical
CFD Analysis for Heat Transfer Enhancement of a Corrugated Plate Heat Exchang...ijtsrd
The flow properties of heat transfer across such corrugated channels are very distinct from parallel plate channels. The primary flow direction is parallel to the waviness of the channel of the corrugated channel, although the local flow direction is still changed due to the waviness of the channel. By flow recirculation, separation and re attachment, the thermal boundary layer formed on its walls is regularly disrupted and the convective heat transfer coefficient is thus increased. In this work, in corrugated channels, the convective heat transfer and pressure drop characteristics of flow have been tested numerically. On channels of uniform heat flux and fixed corrugation over a Reynolds number spectrum, 10000 = Re = 30000, numerical research was conducted. The impacts of channel configuration, variation in Reynold’s number, and concentration variations of nanoparticles in base fluid on heat transfer are discussed. As opposed to the traditional corrugated channel, a major heat transfer gain was associated with the proposed corrugated channel. Based on the nanofluid concentration, Reynold number and channel configuration of the corrugated channel, the average Nusselt number increased by a factor of 2.2 up to 2.8 compared to that of the semi circular corrugated channel. Compared with the effect of channel configuration variation, triangular corrugated channel was the best Nusselt numbers, followed by the shape Semi circular Triangular , and Semi circular corrugated channel with the lowest results. Prof. Pushparaj Singh | Rishi Kesh Jha "CFD Analysis for Heat Transfer Enhancement of a Corrugated Plate Heat Exchanger using Different Corrugated Channel Configurations" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-6 , October 2020, URL: https://www.ijtsrd.com/papers/ijtsrd35706.pdf Paper Url: https://www.ijtsrd.com/engineering/mechanical-engineering/35706/cfd-analysis-for-heat-transfer-enhancement-of-a-corrugated-plate-heat-exchanger-using-different-corrugated-channel-configurations/prof-pushparaj-singh
A Review on “Investigation of Heat Transfer Enhancement of Flow over the dimp...IRJET Journal
This document reviews investigations into using triangular dimple shapes on the internal surface of a divergent duct to enhance heat transfer. A divergent duct promotes fluid mixing and reduces pressure drop compared to a cylindrical pipe. The addition of triangular dimples, which act as an extended surface, can further increase heat transfer by 40-50% over a plain divergent duct. Previous studies have found triangular dimple shapes provide the highest heat transfer enhancement compared to other surface shapes like cylinders or fins. The enhanced mixing in a divergent duct with internal triangular dimples can improve heat transfer for applications in industries like food processing and chemicals.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Analysis of Heat Generation in Double Pipe Heat Exchanger: An Experimental Ev...IRJET Journal
This document summarizes research on analyzing heat generation in a double pipe heat exchanger with an elliptical fin surface contact. An experiment was conducted to compare the heat transfer rate of an elliptical fin to other fin types (tube-tube, rectangular, annular, spiral rod). The results showed the elliptical fin had a higher heat transfer rate. The document reviews several other studies analyzing different fin geometries, heat transfer optimization techniques, and computational fluid dynamics simulations of heat exchangers. It provides background on analyzing heat exchangers using methods like logarithmic mean temperature difference and effectiveness-NTU and discusses prior work optimizing dimensions, materials, and flow conditions to improve heat transfer performance.
Review on Effect of Chevron Angle and Numerical Investigation of Dimensionles...IRJET Journal
The document reviews the effect of chevron angle and numerical investigation of dimensionless numbers in plate heat exchangers. It discusses previous research that has examined heat transfer coefficients and pressure drops at different chevron angles. The paper aims to design a plate heat exchanger using different chevron angles and evaluate heat transfer performance through simulation analysis of numbers like Nusselt, Reynolds, and Prandtl.
Experimental investigation of flow condensation heat transfer in rectangular ...IAEME Publication
This document summarizes an experimental investigation of flow condensation heat transfer in a rectangular minichannel. The study measured condensation heat transfer coefficients and pressure drops for steam condensing in a horizontal aluminum minichannel with a hydraulic diameter of 2mm, where water was used as the coolant. Results showed that the heat transfer coefficients and pressure drops increased with increasing mass flux and vapor quality, due to higher vapor shear forces and thinner liquid films. The experimental data was also compared to existing correlations from other studies on minichannel condensation heat transfer.
Design & optimization of LNG-CNG cylinder for optimum weightijsrd.com
In current automobile sector, the weight of the vehicle is too important to increase the efficiency of the vehicle. There are too many component or subassemblies are in the automobile vehicle. In this paper the weight of the HYDROGEN fuel tank is optimized by applying the composite material concept with the existing material of the fuel tank. Initially the dimensional calculation for the existing pressure vessel and compare with the existing cylinder and then the FEA ( Finite Element Analysis) applied on the cylinder and material optimize up to the stress reaching equivalent to the stress of the existing cylinder. After that the dimension of the cylinder are finalize. The analysis yields a weight reduction of fuel tank.
IRJET-Numerical Investigation of Heat Performance Enhancement for a Double-Pi...IRJET Journal
This document presents a numerical investigation of heat transfer enhancement in a double-pipe heat exchanger with continuous helical baffles in the annulus and either water or alumina nanofluid as the working fluid. The study varies baffle spacing, mass flow rate, and nanofluid concentration to analyze their effects on heat transfer rate, pressure drop, and thermal performance. Results show that adding helical baffles increases the fluid flow path and turbulence, enhancing heat transfer. Replacing water with nanofluid further improves heat transfer while also increasing pressure drop. Graphs comparing the different configurations are presented and agree with previous research findings. The goal is to optimize baffle design and nanofluid parameters to maximize heat transfer rate and performance for practical
This document summarizes a CFD analysis of a tee-configured mixing pipe. The analysis varied the velocity of inlet 1 while keeping inlet 2 velocity fixed. It found that increasing inlet 1 velocity by 50% to 3.75 m/s produced the most homogeneous temperature distribution at the outlet. Visualizations of the temperature and velocity fields helped explain the mixing mechanisms and showed improved penetration of the cold stream into the hot stream with the higher inlet 1 velocity, enhancing mixing. The analysis also identified locations of maximum thermal stress within the pipe.
International Journal of Engineering Inventions (IJEI) provides a multidisciplinary passage for researchers, managers, professionals, practitioners and students around the globe to publish high quality, peer-reviewed articles on all theoretical and empirical aspects of Engineering and Science.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
IRJET- Numerical Analysis of Slurry Flow Characteristics Through Horizontal P...IRJET Journal
This document summarizes a numerical study of slurry flow characteristics in a horizontal pipeline using computational fluid dynamics (CFD). The study models the flow of particles 0.125 mm in size and 2.47 specific gravity through a 4m long, 54.9 mm diameter pipe. Simulations were conducted at velocities of 2 m/s and 5 m/s and particle concentrations of 30% and 40% to analyze solid concentration distribution, velocity distribution, and pressure drop. An Eulerian two-phase model with RNG k-epsilon turbulence modeling was used to simulate the solid-liquid flow and solve the governing equations throughout the computational domain.
FLOW DISTRIBUTION NETWORK ANALYSIS FOR DISCHARGE SIDE OF CENTRIFUGAL PUMPijiert bestjournal
A computational fluid dynamics (CFD) analysis has been conducted to f ind the pressure losses for dividing and combining fluid flow through a junction of discharge system. Si mulations are performed for a range of flow ratios and equations are developed for pressure loss coeff icients at junctions. A mathematical model based on successive approximations then would be employed to estim ate the pressure losses. The proposed CFD based strategy can be used for the analysis of all the thr ee pipe branches of some diameter are selected along with equal length so that only the effect of bend angle can be studied. The effect of bend angle,pipe diameter,pipe length,Reynolds number on the resistance coeffi cient is studied. The software used is CATIA for modeling and ANSYS fluent for analysis purpose.
CFD Analysis of Concentric Tube Heat Exchanger Using Twisted TapesIJARIIT
In this paper, the three dimensional CFD modeling studies on heat transfer, friction factor and thermal performance
of concentric tube heat exchanger using twisted tapes (Plain, V-cut, , Jagged V-cut) with different twist ratios (y=2.0, 4.0) are
used. Twisted tapes are used to augment the heat transfer by creating turbulence in the fluid flow. Various methods are applied
to increase thermal performance of heat transfer devices such as treated surfaces, rough surfaces, swirling flow devices, coiled
tubes, and surface tension devices. Out of these twisted tape method is used to increase the thermal performance. Twisted tape
inserts on effectiveness of heat exchanger has analyzed for different Reynolds Number. The maximum thermal performance
factor was obtained by the Jagged V-cut twisted tape (H=50) insert compare to other twisted tapes. Simultaneously the friction
factor has been analyzed
This document summarizes a numerical simulation study of heat transfer enhancement in a tube fitted with rod helical tape swirl generators. The study uses ANSYS Fluent to model heat transfer and flow characteristics of air flowing inside a circular tube with different tube insert configurations. Results are compared to experimental and analytical calculations from other studies. Enhanced heat transfer is observed with decreasing twist ratio of the helical tape inserts. Heat flux is also found to be more uniform along the tube length with the inserts.
Pressure Dependent of Melting Temperature for MgO and Hcp Ironijtsrd
The Volume dependence of the Grüneisen parameter has been used to calculate the pressure dependence of melting temperature for MgO and hcp iron using Lindemann law. The Volume dependence of the Grüneisen Parameter has been determined using gamma volume V relationship due to Al'tshuler and reciprocal gamma volume V relationship due to Srivastava et al. The calculations are performed between pressure range 55GPa 330GPa. The values of Melting temperature are calculated at different pressures and compared with the available data reported in the literature. Dr. Sheelendra Kumar Yadav "Pressure Dependent of Melting Temperature for MgO and Hcp Iron" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-4 , June 2020, URL: https://www.ijtsrd.com/papers/ijtsrd31434.pdf Paper Url :https://www.ijtsrd.com/other-scientific-research-area/physics/31434/pressure-dependent-of-melting-temperature-for-mgo-and-hcp-iron/dr-sheelendra-kumar-yadav
Surface treatment of high density polyethylene (HDPE) film by 50 Hz dielectri...IJERA Editor
Thin films of high density polyethylene (HDPE) are treated for improving hydrophilicity using non-thermal plasma generated by 50 Hz line frequency dielectric barrier discharge produced in air and argon/air mixture at atmospheric pressure. HDPE samples before and after the treatment are studied using contact angle measurements, surface free energy calculations and atomic force microscopy (AFM). Distilled water (H2O), glycerol (C3H8O3) and diiodomethane (CH2I2) are used as test liquids. The contact angle measurements between test liquids and HDPE samples are used to determine total surface free energy using sessile drop technique. HDPE films show a remarkable increase in surface free energy after plasma treatment. AFM analysis of the plasma-treated HDPE films shows that plasma treatment introduces greater roughness on the surface leading to the increased surface free energy. Furthermore, it is found that introducing a small quantity of argon can enhance the surface treatment remarkably.
REVIEW OF FLOW DISTRIBUTION NETWORK ANALYSIS FOR DISCHARGE SIDE OF CENTRIFUGA...ijiert bestjournal
A computational fluid dynamics (CFD) analysis has been conducted to find the pressure losses for dividing and combining fluid flow through a junction of discharge system. Simulations are performed for a range of flow ratios and equations are developed for pressure loss coefficients at junctions. A mathematical model based on s uccessive approximations then would be employed to estimate the pressure losses. The proposed CFD based strategy can be used for the analysis of all the three pipe branches of s ome diameter are selected along with equal length so that only the effect of bend angle can be st udied. The effect of bend angle,pipe diameter,pipe length,reynolds number on the resistan ce coefficient is studied. The software used is CATIA for modeling and ANSYS fluent for analysis purpose.
MHD Stagnation Point Flow of a Jeffrey Fluid Over a
Stretching/Shrinking Sheet Through Porous Medium by Eswara Rao M and Krishna Murthy M* in COJ Electronics & Communications
technoloTwo dimensional numerical simulation of the combined heat transfer in...ijmech
A numerical investigation was conducted to analyze the flow field and heat transfer characteristics in a vertical channel withradiation and blowing from the wall. Hydrodynamic behaviour and heat transfer results are obtained by the solution of the complete Navier–Stokesand energy equations using a control volume finite element method. Turbulent flow with "Low Reynolds Spalart-Allmaras Turbulence Model" and radiation with "Discrete Transfer Radiation Method" had been modeled. In order to have a complete survey, this article has a wide range of study in different domains including velocity profiles at different locations, turbulent viscosity, shear stress, suctioned mass flow rate in different magnitude of the input
Rayleigh number, blowing Reynoldsnumber, radiation parameter, Prandtl number, the ratio of length to width and also ratio of opening thickness to width of the channel. In addition, effects of variation in any of the above non-dimensional numbers on parameters of the flow are clearly illustrated. At the end resultants had been compared with experimental data which demonstrated that in the present study, results have a great accuracy, relative errors are very small and the curve portraits are in a great
agreement with real experiments.
This document discusses air transient cooling characteristics in the entry regions of ducts with non-circular cross sections. It presents correlations and equations to calculate the hydrodynamic and thermal entrance lengths for triangular, rectangular, circular and square ducts. It also provides equations for the local Nusselt number and convective heat transfer coefficient in the combined entry region where the flow is both thermally and hydrodynamically developing. The analysis considers the transient heat transfer in the duct entry regions using temperature-dependent air properties and numerical modeling. The results indicate that the triangular duct enhances heat transfer the most compared to the other cross section ducts.
STEADY FLOW OF A VISCOUS FLUID THROUGH A SATURATED POROUS MEDIUM AT A CONSTAN...Journal For Research
In this paper the Steady flow of a viscous fluid through a porous medium over a fixed horizontal, impermeable and thermally insulated bottom. The flow through the porous medium satisfies the general momentum and energy equations are obtained when the temperature on the fixed bottom and on free surface prescibed. By using Galerkin Method, the expression for Velocity and Drag force are obtained. The Galerkin Method endowed with distinct features that account for its superiority over competing methods. The effect of different parameters on Velocity and Drag force are discussed with the help of graphs.
Assessment of Performance Characteristic of Solar Air Heater with Assorted Ge...IJERA Editor
Artificial roughness is an efficient way for increasing the heat transfer rate in solar air heater with the
corresponding improvement in its thermal performance. A viscous sub-layer is responsible for the low heat
transfer coefficient between absorber plate and flowing air. Repeated ribs in form of artificial roughness are an
effective way to increase the heat transfer rate and improving the performance of solar air heater. Artificial
roughness of the absorber plate is much economical and effective way to improve the thermal performance of
solar air heater. Several investigators have done various investigations to improve heat transfer coefficient with
little penalty of friction factor. They have also developed different correlation for heat transfer coefficient and
friction factor. The correlations developed for heat transfer and friction factor by various investigators have been
reviewed and presented.
IRJET- Investigation of Fluid Flow Characteristics for the Forced Convect...IRJET Journal
This document summarizes a study that used computational fluid dynamics (CFD) to investigate fluid flow characteristics over heated elliptical and circular shaped tubes. The study varied the Reynolds number from 438 to 1227 and found that elliptical tubes had lower pressure drop and friction factor values than circular tubes. Velocity distributions showed smaller wakes behind elliptical tubes. Pressure drop and friction factor both increased with Reynolds number but elliptical tubes performed better in both areas. The study concluded elliptical tubes provided better heat transfer characteristics than circular tubes of the same hydraulic diameter.
This document summarizes a study on magnetohydrodynamic (MHD) boundary layer flow of a Maxwell fluid past a porous stretching sheet with viscous dissipation. The study investigates the effects of various parameters on heat transfer for two cases: (1) a surface with prescribed wall temperature (PST), and (2) a surface with prescribed wall heat flux (PHF). Governing partial differential equations for momentum and heat transfer are converted to ordinary differential equations using similarity transformations. Numerical solutions are obtained using a shooting technique with a fourth-order Runge-Kutta scheme. Results for different dimensionless parameters are presented graphically for both PST and PHF cases and discussed.
This document summarizes a study that used computational fluid dynamics (CFD) to simulate and predict the velocity and pressure distribution inside a hydrocyclone. The study used commercial CFD software (FLUENT) to model the turbulent swirling flow. The results showed contours and diagrams of pressure and velocity inside the hydrocyclone, with lower pressure observed at the center and an average velocity of 7.173 m/s that agreed with theoretical calculations. Prior studies that also used CFD to model hydrocyclone flow fields and particle trajectories were discussed. The objective of this study was to better understand hydrocyclone flow behavior and separation mechanisms to improve hydrocyclone design and performance.
CFD Coursework: An Investigation on a Static MixerAnthony Man
This document summarizes a CFD study conducted on a static mixer. Three key phases were completed:
1) A baseline mesh was created and the effect of modeling the boundary layer was investigated. It was found modeling the boundary layer improved accuracy.
2) A parameter study was done using inlet diameter and angle, finding outlet temperature range increased with diameter and lower second inlet angle.
3) Different turbulence models were tested, with K-ε found to be most suitable for the highly turbulent flow in the static mixer.
IRJET- Enhancement of Heat Transfer Effectiveness of Plate-Pin Fin Heat S...IRJET Journal
This document summarizes a study on enhancing the heat transfer effectiveness of plate-pin fin heat sinks. Nineteen different plate-pin fin heat sink models were numerically simulated and analyzed based on factors like heat transfer coefficient, Nusselt number, pressure drop, base plate temperature, fan power, and thermal resistance. The results showed that a plate-pin fin heat sink model with a plate cut thickness of D/3, where D is the pin diameter, performed the best with higher heat transfer coefficient, Nusselt number, and lower base plate temperature, pressure drop, fan power, and thermal resistance compared to other models. A heat sink model with pin fins containing two holes also showed improved performance over solid pin fins.
CFD Analysis of Heat Transfer in Helical CoilIRJET Journal
This document presents a computational fluid dynamics (CFD) analysis of heat transfer in a helical coil. The study aims to analyze the effect of coil diameter and inlet steam temperature on the heat transfer coefficient. CFD simulations are conducted for helical coils of different diameters with varying inlet steam temperatures and water flow rates. Results show that the heat transfer coefficient increases with increasing inlet steam temperature. Prior research on heat transfer in helical coils is also reviewed, focusing on studies utilizing CFD to analyze parameters like coil diameter, pitch, curvature ratio, and Reynolds number. The CFD methodology and boundary conditions used in this study are described. Contour plots of the simulated surface heat transfer coefficient are presented and discussed.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparative Study of ECONOMISER Using the CFD Analysis IJMER
This paper presents a simulation of the economizer zone, which allowsstudying the flow
patterns developed in the fluid, while it flows along the length of the economizer. The past failure
details revelsthat erosion is more in U-bend areas of Economizer Unit because of increase in flue gas
velocity near these bends. But it isobserved that the velocity of flue gases surprisingly increases near
the lower bends as compared to upper ones. The model issolved using conventional CFD techniques by
FLUENT software. In which the individual tubes are treated as sub-gridfeatures. A geometrical model
is used to describe the multiplicity of heat-exchanging structures and the interconnectionsamong them.
The Computational Fluid Dynamics (CFD) approach is utilised for the creation of a three-dimensional
modelof the economizer coil of single column tube. With equilibrium assumption applied for
description of the system chemistry. The flue gastemperature, pressure and velocity field of fluid flow
within an economizer tube using the actual bounda
This document summarizes a CFD analysis of a tee-configured mixing pipe. The analysis varied the velocity of inlet 1 while keeping inlet 2 velocity fixed. It found that increasing inlet 1 velocity by 50% to 3.75 m/s produced the most homogeneous temperature distribution at the outlet. Visualizations of the temperature and velocity fields helped explain the mixing mechanisms and showed improved penetration of the cold stream into the hot stream with the higher inlet 1 velocity, enhancing mixing. The analysis also identified locations of maximum thermal stress within the pipe.
International Journal of Engineering Inventions (IJEI) provides a multidisciplinary passage for researchers, managers, professionals, practitioners and students around the globe to publish high quality, peer-reviewed articles on all theoretical and empirical aspects of Engineering and Science.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
IRJET- Numerical Analysis of Slurry Flow Characteristics Through Horizontal P...IRJET Journal
This document summarizes a numerical study of slurry flow characteristics in a horizontal pipeline using computational fluid dynamics (CFD). The study models the flow of particles 0.125 mm in size and 2.47 specific gravity through a 4m long, 54.9 mm diameter pipe. Simulations were conducted at velocities of 2 m/s and 5 m/s and particle concentrations of 30% and 40% to analyze solid concentration distribution, velocity distribution, and pressure drop. An Eulerian two-phase model with RNG k-epsilon turbulence modeling was used to simulate the solid-liquid flow and solve the governing equations throughout the computational domain.
FLOW DISTRIBUTION NETWORK ANALYSIS FOR DISCHARGE SIDE OF CENTRIFUGAL PUMPijiert bestjournal
A computational fluid dynamics (CFD) analysis has been conducted to f ind the pressure losses for dividing and combining fluid flow through a junction of discharge system. Si mulations are performed for a range of flow ratios and equations are developed for pressure loss coeff icients at junctions. A mathematical model based on successive approximations then would be employed to estim ate the pressure losses. The proposed CFD based strategy can be used for the analysis of all the thr ee pipe branches of some diameter are selected along with equal length so that only the effect of bend angle can be studied. The effect of bend angle,pipe diameter,pipe length,Reynolds number on the resistance coeffi cient is studied. The software used is CATIA for modeling and ANSYS fluent for analysis purpose.
CFD Analysis of Concentric Tube Heat Exchanger Using Twisted TapesIJARIIT
In this paper, the three dimensional CFD modeling studies on heat transfer, friction factor and thermal performance
of concentric tube heat exchanger using twisted tapes (Plain, V-cut, , Jagged V-cut) with different twist ratios (y=2.0, 4.0) are
used. Twisted tapes are used to augment the heat transfer by creating turbulence in the fluid flow. Various methods are applied
to increase thermal performance of heat transfer devices such as treated surfaces, rough surfaces, swirling flow devices, coiled
tubes, and surface tension devices. Out of these twisted tape method is used to increase the thermal performance. Twisted tape
inserts on effectiveness of heat exchanger has analyzed for different Reynolds Number. The maximum thermal performance
factor was obtained by the Jagged V-cut twisted tape (H=50) insert compare to other twisted tapes. Simultaneously the friction
factor has been analyzed
This document summarizes a numerical simulation study of heat transfer enhancement in a tube fitted with rod helical tape swirl generators. The study uses ANSYS Fluent to model heat transfer and flow characteristics of air flowing inside a circular tube with different tube insert configurations. Results are compared to experimental and analytical calculations from other studies. Enhanced heat transfer is observed with decreasing twist ratio of the helical tape inserts. Heat flux is also found to be more uniform along the tube length with the inserts.
Pressure Dependent of Melting Temperature for MgO and Hcp Ironijtsrd
The Volume dependence of the Grüneisen parameter has been used to calculate the pressure dependence of melting temperature for MgO and hcp iron using Lindemann law. The Volume dependence of the Grüneisen Parameter has been determined using gamma volume V relationship due to Al'tshuler and reciprocal gamma volume V relationship due to Srivastava et al. The calculations are performed between pressure range 55GPa 330GPa. The values of Melting temperature are calculated at different pressures and compared with the available data reported in the literature. Dr. Sheelendra Kumar Yadav "Pressure Dependent of Melting Temperature for MgO and Hcp Iron" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-4 , June 2020, URL: https://www.ijtsrd.com/papers/ijtsrd31434.pdf Paper Url :https://www.ijtsrd.com/other-scientific-research-area/physics/31434/pressure-dependent-of-melting-temperature-for-mgo-and-hcp-iron/dr-sheelendra-kumar-yadav
Surface treatment of high density polyethylene (HDPE) film by 50 Hz dielectri...IJERA Editor
Thin films of high density polyethylene (HDPE) are treated for improving hydrophilicity using non-thermal plasma generated by 50 Hz line frequency dielectric barrier discharge produced in air and argon/air mixture at atmospheric pressure. HDPE samples before and after the treatment are studied using contact angle measurements, surface free energy calculations and atomic force microscopy (AFM). Distilled water (H2O), glycerol (C3H8O3) and diiodomethane (CH2I2) are used as test liquids. The contact angle measurements between test liquids and HDPE samples are used to determine total surface free energy using sessile drop technique. HDPE films show a remarkable increase in surface free energy after plasma treatment. AFM analysis of the plasma-treated HDPE films shows that plasma treatment introduces greater roughness on the surface leading to the increased surface free energy. Furthermore, it is found that introducing a small quantity of argon can enhance the surface treatment remarkably.
REVIEW OF FLOW DISTRIBUTION NETWORK ANALYSIS FOR DISCHARGE SIDE OF CENTRIFUGA...ijiert bestjournal
A computational fluid dynamics (CFD) analysis has been conducted to find the pressure losses for dividing and combining fluid flow through a junction of discharge system. Simulations are performed for a range of flow ratios and equations are developed for pressure loss coefficients at junctions. A mathematical model based on s uccessive approximations then would be employed to estimate the pressure losses. The proposed CFD based strategy can be used for the analysis of all the three pipe branches of s ome diameter are selected along with equal length so that only the effect of bend angle can be st udied. The effect of bend angle,pipe diameter,pipe length,reynolds number on the resistan ce coefficient is studied. The software used is CATIA for modeling and ANSYS fluent for analysis purpose.
MHD Stagnation Point Flow of a Jeffrey Fluid Over a
Stretching/Shrinking Sheet Through Porous Medium by Eswara Rao M and Krishna Murthy M* in COJ Electronics & Communications
technoloTwo dimensional numerical simulation of the combined heat transfer in...ijmech
A numerical investigation was conducted to analyze the flow field and heat transfer characteristics in a vertical channel withradiation and blowing from the wall. Hydrodynamic behaviour and heat transfer results are obtained by the solution of the complete Navier–Stokesand energy equations using a control volume finite element method. Turbulent flow with "Low Reynolds Spalart-Allmaras Turbulence Model" and radiation with "Discrete Transfer Radiation Method" had been modeled. In order to have a complete survey, this article has a wide range of study in different domains including velocity profiles at different locations, turbulent viscosity, shear stress, suctioned mass flow rate in different magnitude of the input
Rayleigh number, blowing Reynoldsnumber, radiation parameter, Prandtl number, the ratio of length to width and also ratio of opening thickness to width of the channel. In addition, effects of variation in any of the above non-dimensional numbers on parameters of the flow are clearly illustrated. At the end resultants had been compared with experimental data which demonstrated that in the present study, results have a great accuracy, relative errors are very small and the curve portraits are in a great
agreement with real experiments.
This document discusses air transient cooling characteristics in the entry regions of ducts with non-circular cross sections. It presents correlations and equations to calculate the hydrodynamic and thermal entrance lengths for triangular, rectangular, circular and square ducts. It also provides equations for the local Nusselt number and convective heat transfer coefficient in the combined entry region where the flow is both thermally and hydrodynamically developing. The analysis considers the transient heat transfer in the duct entry regions using temperature-dependent air properties and numerical modeling. The results indicate that the triangular duct enhances heat transfer the most compared to the other cross section ducts.
STEADY FLOW OF A VISCOUS FLUID THROUGH A SATURATED POROUS MEDIUM AT A CONSTAN...Journal For Research
In this paper the Steady flow of a viscous fluid through a porous medium over a fixed horizontal, impermeable and thermally insulated bottom. The flow through the porous medium satisfies the general momentum and energy equations are obtained when the temperature on the fixed bottom and on free surface prescibed. By using Galerkin Method, the expression for Velocity and Drag force are obtained. The Galerkin Method endowed with distinct features that account for its superiority over competing methods. The effect of different parameters on Velocity and Drag force are discussed with the help of graphs.
Assessment of Performance Characteristic of Solar Air Heater with Assorted Ge...IJERA Editor
Artificial roughness is an efficient way for increasing the heat transfer rate in solar air heater with the
corresponding improvement in its thermal performance. A viscous sub-layer is responsible for the low heat
transfer coefficient between absorber plate and flowing air. Repeated ribs in form of artificial roughness are an
effective way to increase the heat transfer rate and improving the performance of solar air heater. Artificial
roughness of the absorber plate is much economical and effective way to improve the thermal performance of
solar air heater. Several investigators have done various investigations to improve heat transfer coefficient with
little penalty of friction factor. They have also developed different correlation for heat transfer coefficient and
friction factor. The correlations developed for heat transfer and friction factor by various investigators have been
reviewed and presented.
IRJET- Investigation of Fluid Flow Characteristics for the Forced Convect...IRJET Journal
This document summarizes a study that used computational fluid dynamics (CFD) to investigate fluid flow characteristics over heated elliptical and circular shaped tubes. The study varied the Reynolds number from 438 to 1227 and found that elliptical tubes had lower pressure drop and friction factor values than circular tubes. Velocity distributions showed smaller wakes behind elliptical tubes. Pressure drop and friction factor both increased with Reynolds number but elliptical tubes performed better in both areas. The study concluded elliptical tubes provided better heat transfer characteristics than circular tubes of the same hydraulic diameter.
This document summarizes a study on magnetohydrodynamic (MHD) boundary layer flow of a Maxwell fluid past a porous stretching sheet with viscous dissipation. The study investigates the effects of various parameters on heat transfer for two cases: (1) a surface with prescribed wall temperature (PST), and (2) a surface with prescribed wall heat flux (PHF). Governing partial differential equations for momentum and heat transfer are converted to ordinary differential equations using similarity transformations. Numerical solutions are obtained using a shooting technique with a fourth-order Runge-Kutta scheme. Results for different dimensionless parameters are presented graphically for both PST and PHF cases and discussed.
This document summarizes a study that used computational fluid dynamics (CFD) to simulate and predict the velocity and pressure distribution inside a hydrocyclone. The study used commercial CFD software (FLUENT) to model the turbulent swirling flow. The results showed contours and diagrams of pressure and velocity inside the hydrocyclone, with lower pressure observed at the center and an average velocity of 7.173 m/s that agreed with theoretical calculations. Prior studies that also used CFD to model hydrocyclone flow fields and particle trajectories were discussed. The objective of this study was to better understand hydrocyclone flow behavior and separation mechanisms to improve hydrocyclone design and performance.
CFD Coursework: An Investigation on a Static MixerAnthony Man
This document summarizes a CFD study conducted on a static mixer. Three key phases were completed:
1) A baseline mesh was created and the effect of modeling the boundary layer was investigated. It was found modeling the boundary layer improved accuracy.
2) A parameter study was done using inlet diameter and angle, finding outlet temperature range increased with diameter and lower second inlet angle.
3) Different turbulence models were tested, with K-ε found to be most suitable for the highly turbulent flow in the static mixer.
IRJET- Enhancement of Heat Transfer Effectiveness of Plate-Pin Fin Heat S...IRJET Journal
This document summarizes a study on enhancing the heat transfer effectiveness of plate-pin fin heat sinks. Nineteen different plate-pin fin heat sink models were numerically simulated and analyzed based on factors like heat transfer coefficient, Nusselt number, pressure drop, base plate temperature, fan power, and thermal resistance. The results showed that a plate-pin fin heat sink model with a plate cut thickness of D/3, where D is the pin diameter, performed the best with higher heat transfer coefficient, Nusselt number, and lower base plate temperature, pressure drop, fan power, and thermal resistance compared to other models. A heat sink model with pin fins containing two holes also showed improved performance over solid pin fins.
CFD Analysis of Heat Transfer in Helical CoilIRJET Journal
This document presents a computational fluid dynamics (CFD) analysis of heat transfer in a helical coil. The study aims to analyze the effect of coil diameter and inlet steam temperature on the heat transfer coefficient. CFD simulations are conducted for helical coils of different diameters with varying inlet steam temperatures and water flow rates. Results show that the heat transfer coefficient increases with increasing inlet steam temperature. Prior research on heat transfer in helical coils is also reviewed, focusing on studies utilizing CFD to analyze parameters like coil diameter, pitch, curvature ratio, and Reynolds number. The CFD methodology and boundary conditions used in this study are described. Contour plots of the simulated surface heat transfer coefficient are presented and discussed.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparative Study of ECONOMISER Using the CFD Analysis IJMER
This paper presents a simulation of the economizer zone, which allowsstudying the flow
patterns developed in the fluid, while it flows along the length of the economizer. The past failure
details revelsthat erosion is more in U-bend areas of Economizer Unit because of increase in flue gas
velocity near these bends. But it isobserved that the velocity of flue gases surprisingly increases near
the lower bends as compared to upper ones. The model issolved using conventional CFD techniques by
FLUENT software. In which the individual tubes are treated as sub-gridfeatures. A geometrical model
is used to describe the multiplicity of heat-exchanging structures and the interconnectionsamong them.
The Computational Fluid Dynamics (CFD) approach is utilised for the creation of a three-dimensional
modelof the economizer coil of single column tube. With equilibrium assumption applied for
description of the system chemistry. The flue gastemperature, pressure and velocity field of fluid flow
within an economizer tube using the actual bounda
FLUID FLOW ANALYSIS IN AIR DUCT FLOW WITH AND WITHOUT INTERNAL THREADS USING ...IAEME Publication
Computational heat transfer flow modeling is one of the great challenges in the classical sciences. As with most problems in engineering, the interest in the heat transfer augmentation is increasing due to its extreme importance in various industrial applications. This paper deals with the analysis of heat transfer for fluid flowing through the pipe with and without internal threads using CFD. Using CFD codes for modeling the heat and fluid flow is an efficient tool for predicting equipment performance. CFD offers a convenient means to study the detailed flows and heat exchange processes, which take place inside the tube. Simulations were carried out using commercial CFD software ANSYS Fluent version 14.5. Friction factor and Nusselt number for air flowing through the specified tube (internal diameter = 0.005 m, length = 0.1 m) were obtained first for the plain tube and then for the tube with internal threads with pitch 5mm in the Reynolds number range of 2000 to 5000. Finally results will be compared to available experimental and analytical calculations. The data obtained by simulation are matching with the literature value for a plain tube with the discrepancy of less than plus or minus 5% for Nusselt number and for the friction factor.
Enhanced heat transfer for the tube with internal threads has been observed. Heat flux is more uniform all along the tube and decreases uniformly towards the center.
Computational Fluid Dynamics (CFD) Analysis of Natural Convection of Converge...IJERA Editor
Computational Fluid Dynamics (CFD) analysis was carried out for the convergent-divergent fins arranged inline and staggered on the base plate as per the experimental setup provided in the technical paper [1]. This paper reports on the validation of results of modeling and simulation in CFD. The simulation was carried out using the ANSYS 12.0 as the CFD modeling software. The main objective of the CFD analysis was to calculate the temperature distribution on the surface of the base plate and surface of the convergent-divergent fins for the given inline and staggered arrangement of fins due to the effect of natural convection heat transfer for different heat power inputs, and also to compare the CFD results with the experimental results.
The document presents a theoretical and statistical model for predicting flux in direct contact membrane distillation (DCMD). Theoretical models are applied to predict DCMD performance based on heat and mass transfer analysis. Statistical analysis of variance (ANOVA) is used to determine the effect of operating parameters on performance. A regression model is developed for predicting flux and shows good agreement with experimental data and the theoretical model. Feed temperature, flow rates, and other parameters are considered in both the theoretical and statistical models.
Theoretical and Statistical Models for Predicting Flux in Direct Contact Memb...IJERA Editor
Theoretical modelhas been applied to predict the performance of Direct Contact Membrane Distillation (DCMD) based on the analysis of heat and mass transfer through the membrane. The performance of DCMD on the account of different operating parameters had been predicted. Feed inlet temperature, coolant inlet temperature, feed flow rate and coolant flow rate are the considered performance variables. Based on the data obtained from theoretical model, statistical analysis of variance (ANOVA) was then performed to determine the significant effect of each operating factors on the DCMD system performance. A new regression model was subsequently developed for predicting the performance of the DCMD system. Resultsrevealed that both theoretical and regression models were in good agreement with each other and also with the selected experimental data used for validation. The maximum percentage error between the two models was found to be1.098%. Hence, the developed regression model is adequate for predict the performance of DCMD system within the domain of the considered analysis. Keywords– Water Desalination, Direct contact membrane distillation, theoretical modelling, ANOVA, Taguchi methodology, regression model.
Heat Transfer Enhancement Using Aluminium Oxide Nanofluid: Effect of the Base...CSCJournals
The flow and heat transfer is an important phenomenon in engineering systems due to its wide application in electronic cooling, heat exchangers, double pane windows etc.. The enhancement of heat transfer in these systems is an essential topic from an energy saving perspective. The lower heat transfer performance when conventional fluids, such as water, engine oil and ethylene glycol are used hinders improvements in performance and a consequent reduction in the size of such systems. The use of solid particles as an additive suspended into the base fluid is a technique for heat transfer enhancement. Therefore, the heat transfer enhancement in a horizontal circular tube that is maintained at a constant temperature under laminar regime has been investigated numerically. A computational code applied to the problem by use of the finite volume method was developed. Nanofluid was made by dispersion of Al2O3 nanoparticles in pur water and ethylene glycol. Results illustrate that the suspended nanoparticles increase the heat transfer with an increase in the nanoparticles volume fraction and for a considered range of Reynolds numbers. And in other hand, the heat transfer is very sensitive to the base fluid.
Computational analysis for different characteristics of the circular microcha...IRJET Journal
This document summarizes research on computational analysis of flow characteristics in circular microchannels under low Reynolds number conditions. It discusses how a variable diameter design can improve flow rate and heat dissipation from electronic chips. The document reviews several past studies on microchannel flow and heat transfer. It is found that increasing the microchannel diameter increases heat dissipation rate, with a proposed design improving flow rate and heat removal for chip cooling.
Analytical and Experimental analysis ofthermal characteristics throughTriangu...IJERA Editor
Microscale heat transfer technique is widely intended for best cooling applications in electronic devices as high
heat transfer coefficients are achieved in microscale convection. In present study, analysis of thermal
characteristics has been carried out by analytical calculations along with experimental investigation for a straight
microchannel heat sink of equilateral triangular cross section of 173.21 μm hydraulic diameter with distilled
water as the working fluid. Designed Heater input watts and Reynolds number based on flow rate are varied for
optimized microchannel geometry. Experimental analysis is carried out under constant heat flux condition. The
microchannels are produced on highly accurate micro wire cut EDM. The Reynolds number is varied from 100
to 700. The major intension for this work is to enhance heat transfer coefficient and minimize pressure drop
across microchannel. The Reynolds number, temperature distribution, pressure distribution, heat transfer
coefficient, hydrodynamic entrance length, thermal entrance length, equivalent thermal resistances parameters
are calculated for microchannel heat sink performance analysis. The results of analytical calculations are verified
with experimental investigation. It is found that heat transfer coefficient and pressure drop increases with
increase in Reynolds numbers and decrease in microchannel heat sink hydraulic diameter. Also channel length is
directly proportional to temperature rise
A Study on Various Heat Transfer Enhancement TechniquesIRJET Journal
This document summarizes research on various heat transfer enhancement techniques, including wavy fins, louvered fins, and different tube shapes. It discusses how constructal theory can be used to optimize the configuration of wavy and louvered fins to improve thermal performance. Several studies that analyzed parameters like fin pitch and louver angle are summarized. The results showed that an optimal design using constructal theory can improve heat transfer by 14-32% while maintaining pressure drop. For wavy fins, an amplitude ratio of around 0.7 performed well. The document also analyzes different tube shapes, finding that a circular cross-section performed most efficiently, with lower turbulence than elliptical or oval shapes.
A Review on Enhancement of Heat Transfer Rate by Various Passive MethodsIRJET Journal
This document reviews various passive methods that have been used to enhance heat transfer rates in heat exchangers. It summarizes 15 research papers that studied techniques like using corrugated tubes, twisted tapes, nanofluids, and ribbed surfaces to increase heat transfer surface area and turbulence. Computational fluid dynamics simulations and experiments on different heat exchanger designs found that these passive methods can increase heat transfer rates by up to 60% while also increasing pressure drop. The optimal designs and flow conditions depended on factors like geometry, Reynolds number, and mass flow rates. Overall, passive inserts and surface modifications were shown to effectively enhance heat transfer in heat exchangers.
CFD Investigation of Compact Heat Exchanger Having Different Fins with Nanofl...IRJET Journal
This document summarizes research on using computational fluid dynamics (CFD) to investigate heat transfer in a compact heat exchanger with different fin types and titanium dioxide nanofluid. It discusses past research on various techniques for enhancing heat transfer and reducing pressure losses in heat exchangers. The document then outlines the objectives, methodology, and potential implications of research using CFD and limited experimental data to develop new heat transfer and pressure drop correlations for plain, offset strip, and wavy fins, which are common in applications like cryogenics and aerospace. These new correlations could provide more accurate and broadly applicable insights for heat exchanger design compared to existing correlations.
IRJET-Numerical Investigation on Performance of VCR System using Shell and Tu...IRJET Journal
This document discusses numerically investigating the performance of a vapor compression refrigeration (VCR) system using different types of heat exchangers. It aims to replace an existing double pipe heat exchanger (DPHE) with a shell and tube heat exchanger (STHE) to improve efficiency. CFD analysis is conducted on both heat exchangers to compare their coefficient of performance (COP). The DPHE currently used has low efficiency, so a STHE is proposed as it has higher efficiency and requires less area. Helical baffles within the STHE may provide further improvements.
A Review on Developments in Technologies of Heat Exchangers WorldwideIRJET Journal
This document reviews developments in heat exchanger technologies worldwide, specifically focusing on helical coil heat exchangers. It summarizes 13 research papers on helical coil heat exchangers, discussing how they enhance heat transfer rates compared to straight tube exchangers and examining factors like coil geometry, fluid properties, and temperature that affect heat transfer performance. The document concludes that while helical coil exchangers provide more efficient heat transfer, correlations to predict performance are impacted by parameters like coil diameter, pitch, and inlet fluid properties and conditions.
IRJET- Review of Convection and Magnetohydrodynamic Mixed Convection Heat Tra...IRJET Journal
This document provides a review of recent research on enhancing heat transfer through convection and magnetohydrodynamic mixed convection. It discusses two main techniques: using extra surfaces like inserts to disrupt thermal boundary layers, and applying magnetic fields in magnetohydrodynamic mixed convection systems. The review summarizes several studies on each technique, finding that extra surfaces generally enhance heat transfer by inducing turbulence, while magnetic fields can both enhance and suppress heat transfer depending on parameters. It concludes that both techniques show promise for improving thermal efficiency and optimizing heat exchanger design.
Thermohydrodynamic analysis of plain journal bearing with modified viscosity ...IAEME Publication
This document summarizes previous research on thermohydrodynamic analysis of journal bearings. It discusses governing equations used in such analyses, including the Reynolds equation and energy equations. It also discusses different viscosity-temperature relationships that have been used and highlights how the authors have modified an existing two-degree viscosity-temperature equation to a three-degree polynomial equation to better predict viscosity variations with temperature in journal bearings. The aim of the paper is to predict pressure and temperature distributions in plain journal bearings using this modified viscosity-temperature relationship.
CFD Analysis to Analyze Thermal Characteristics of a Heat Exchanger Handling ...ijtsrd
It takes a lot of energy to have a good life. For living and working, humans nowadays rely on an abundant and constant source of power. Because energy is depleting at such a rapid rate, it has become important to use heat more efficiently, which necessitates that we preserve. As a result of the global energy crisis, many researchers have worked to improve the efficiency of thermal systems and reduce the size and thus energy consumption rates, which is one of the most critical problems due to the large and continuing increase in consumption, the increasing scarcity of energy resources, and the high cost. A 3 dimensional numerical 3 D simulation was used to evaluate the thermal properties of a heat exchanger managing a combination of dimple ribs. Handling air flow velocity through the channel was varied from 3.97 to 5.80 m s. is the subject of this study. The heat transfer physiognomies of a heat exchanger managing a combination of dimple ribs were studied using the simulation tool ANSYS 19.2. The numerical results showed that the combination of dimple ribs enhanced heat transfer significantly more than the dimple. In comparison, the average Nusselt number of a combination of dimple ribs is 4.28 percent higher than that of a channel with dimpled Plate. Abhishek Singh | Prof. Rohit Soni "CFD Analysis to Analyze Thermal Characteristics of a Heat Exchanger Handling Combination of Dimple Ribs" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-6 , October 2021, URL: https://www.ijtsrd.com/papers/ijtsrd47712.pdf Paper URL : https://www.ijtsrd.com/engineering/mechanical-engineering/47712/cfd-analysis-to-analyze-thermal-characteristics-of-a-heat-exchanger-handling-combination-of-dimple-ribs/abhishek-singh
Submission Deadline: 30th September 2022
Acceptance Notification: Within Three Days’ time period
Online Publication: Within 24 Hrs. time Period
Expected Date of Dispatch of Printed Journal: 5th October 2022
MODELING AND ANALYSIS OF SURFACE ROUGHNESS AND WHITE LATER THICKNESS IN WIRE-...IAEME Publication
White layer thickness (WLT) formed and surface roughness in wire electric discharge turning (WEDT) of tungsten carbide composite has been made to model through response surface methodology (RSM). A Taguchi’s standard Design of experiments involving five input variables with three levels has been employed to establish a mathematical model between input parameters and responses. Percentage of cobalt content, spindle speed, Pulse on-time, wire feed and pulse off-time were changed during the experimental tests based on the Taguchi’s orthogonal array L27 (3^13). Analysis of variance (ANOVA) revealed that the mathematical models obtained can adequately describe performance within the parameters of the factors considered. There was a good agreement between the experimental and predicted values in this study.
A STUDY ON THE REASONS FOR TRANSGENDER TO BECOME ENTREPRENEURSIAEME Publication
The study explores the reasons for a transgender to become entrepreneurs. In this study transgender entrepreneur was taken as independent variable and reasons to become as dependent variable. Data were collected through a structured questionnaire containing a five point Likert Scale. The study examined the data of 30 transgender entrepreneurs in Salem Municipal Corporation of Tamil Nadu State, India. Simple Random sampling technique was used. Garrett Ranking Technique (Percentile Position, Mean Scores) was used as the analysis for the present study to identify the top 13 stimulus factors for establishment of trans entrepreneurial venture. Economic advancement of a nation is governed upon the upshot of a resolute entrepreneurial doings. The conception of entrepreneurship has stretched and materialized to the socially deflated uncharted sections of transgender community. Presently transgenders have smashed their stereotypes and are making recent headlines of achievements in various fields of our Indian society. The trans-community is gradually being observed in a new light and has been trying to achieve prospective growth in entrepreneurship. The findings of the research revealed that the optimistic changes are taking place to change affirmative societal outlook of the transgender for entrepreneurial ventureship. It also laid emphasis on other transgenders to renovate their traditional living. The paper also highlights that legislators, supervisory body should endorse an impartial canons and reforms in Tamil Nadu Transgender Welfare Board Association.
BROAD UNEXPOSED SKILLS OF TRANSGENDER ENTREPRENEURSIAEME Publication
Since ages gender difference is always a debatable theme whether caused by nature, evolution or environment. The birth of a transgender is dreadful not only for the child but also for their parents. The pain of living in the wrong physique and treated as second class victimized citizen is outrageous and fully harboured with vicious baseless negative scruples. For so long, social exclusion had perpetuated inequality and deprivation experiencing ingrained malign stigma and besieged victims of crime or violence across their life spans. They are pushed into the murky way of life with a source of eternal disgust, bereft sexual potency and perennial fear. Although they are highly visible but very little is known about them. The common public needs to comprehend the ravaged arrogance on these insensitive souls and assist in integrating them into the mainstream by offering equal opportunity, treat with humanity and respect their dignity. Entrepreneurship in the current age is endorsing the gender fairness movement. Unstable careers and economic inadequacy had inclined one of the gender variant people called Transgender to become entrepreneurs. These tiny budding entrepreneurs resulted in economic transition by means of employment, free from the clutches of stereotype jobs, raised standard of living and handful of financial empowerment. Besides all these inhibitions, they were able to witness a platform for skill set development that ignited them to enter into entrepreneurial domain. This paper epitomizes skill sets involved in trans-entrepreneurs of Thoothukudi Municipal Corporation of Tamil Nadu State and is a groundbreaking determination to sightsee various skills incorporated and the impact on entrepreneurship.
DETERMINANTS AFFECTING THE USER'S INTENTION TO USE MOBILE BANKING APPLICATIONSIAEME Publication
The banking and financial services industries are experiencing increased technology penetration. Among them, the banking industry has made technological advancements to better serve the general populace. The economy focused on transforming the banking sector's system into a cashless, paperless, and faceless one. The researcher wants to evaluate the user's intention for utilising a mobile banking application. The study also examines the variables affecting the user's behaviour intention when selecting specific applications for financial transactions. The researcher employed a well-structured questionnaire and a descriptive study methodology to gather the respondents' primary data utilising the snowball sampling technique. The study includes variables like performance expectations, effort expectations, social impact, enabling circumstances, and perceived risk. Each of the aforementioned variables has a major impact on how users utilise mobile banking applications. The outcome will assist the service provider in comprehending the user's history with mobile banking applications.
ANALYSE THE USER PREDILECTION ON GPAY AND PHONEPE FOR DIGITAL TRANSACTIONSIAEME Publication
Technology upgradation in banking sector took the economy to view that payment mode towards online transactions using mobile applications. This system enabled connectivity between banks, Merchant and user in a convenient mode. there are various applications used for online transactions such as Google pay, Paytm, freecharge, mobikiwi, oxygen, phonepe and so on and it also includes mobile banking applications. The study aimed at evaluating the predilection of the user in adopting digital transaction. The study is descriptive in nature. The researcher used random sample techniques to collect the data. The findings reveal that mobile applications differ with the quality of service rendered by Gpay and Phonepe. The researcher suggest the Phonepe application should focus on implementing the application should be user friendly interface and Gpay on motivating the users to feel the importance of request for money and modes of payments in the application.
VOICE BASED ATM FOR VISUALLY IMPAIRED USING ARDUINOIAEME Publication
The prototype of a voice-based ATM for visually impaired using Arduino is to help people who are blind. This uses RFID cards which contain users fingerprint encrypted on it and interacts with the users through voice commands. ATM operates when sensor detects the presence of one person in the cabin. After scanning the RFID card, it will ask to select the mode like –normal or blind. User can select the respective mode through voice input, if blind mode is selected the balance check or cash withdraw can be done through voice input. Normal mode procedure is same as the existing ATM.
IMPACT OF EMOTIONAL INTELLIGENCE ON HUMAN RESOURCE MANAGEMENT PRACTICES AMONG...IAEME Publication
There is increasing acceptability of emotional intelligence as a major factor in personality assessment and effective human resource management. Emotional intelligence as the ability to build capacity, empathize, co-operate, motivate and develop others cannot be divorced from both effective performance and human resource management systems. The human person is crucial in defining organizational leadership and fortunes in terms of challenges and opportunities and walking across both multinational and bilateral relationships. The growing complexity of the business world requires a great deal of self-confidence, integrity, communication, conflict and diversity management to keep the global enterprise within the paths of productivity and sustainability. Using the exploratory research design and 255 participants the result of this original study indicates strong positive correlation between emotional intelligence and effective human resource management. The paper offers suggestions on further studies between emotional intelligence and human capital development and recommends for conflict management as an integral part of effective human resource management.
VISUALISING AGING PARENTS & THEIR CLOSE CARERS LIFE JOURNEY IN AGING ECONOMYIAEME Publication
Our life journey, in general, is closely defined by the way we understand the meaning of why we coexist and deal with its challenges. As we develop the "inspiration economy", we could say that nearly all of the challenges we have faced are opportunities that help us to discover the rest of our journey. In this note paper, we explore how being faced with the opportunity of being a close carer for an aging parent with dementia brought intangible discoveries that changed our insight of the meaning of the rest of our life journey.
A STUDY ON THE IMPACT OF ORGANIZATIONAL CULTURE ON THE EFFECTIVENESS OF PERFO...IAEME Publication
The main objective of this study is to analyze the impact of aspects of Organizational Culture on the Effectiveness of the Performance Management System (PMS) in the Health Care Organization at Thanjavur. Organizational Culture and PMS play a crucial role in present-day organizations in achieving their objectives. PMS needs employees’ cooperation to achieve its intended objectives. Employees' cooperation depends upon the organization’s culture. The present study uses exploratory research to examine the relationship between the Organization's culture and the Effectiveness of the Performance Management System. The study uses a Structured Questionnaire to collect the primary data. For this study, Thirty-six non-clinical employees were selected from twelve randomly selected Health Care organizations at Thanjavur. Thirty-two fully completed questionnaires were received.
Living in 21st century in itself reminds all of us the necessity of police and its administration. As more and more we are entering into the modern society and culture, the more we require the services of the so called ‘Khaki Worthy’ men i.e., the police personnel. Whether we talk of Indian police or the other nation’s police, they all have the same recognition as they have in India. But as already mentioned, their services and requirements are different after the like 26th November, 2008 incidents, where they without saving their own lives has sacrificed themselves without any hitch and without caring about their respective family members and wards. In other words, they are like our heroes and mentors who can guide us from the darkness of fear, militancy, corruption and other dark sides of life and so on. Now the question arises, if Gandhi would have been alive today, what would have been his reaction/opinion to the police and its functioning? Would he have some thing different in his mind now what he had been in his mind before the partition or would he be going to start some Satyagraha in the form of some improvement in the functioning of the police administration? Really these questions or rather night mares can come to any one’s mind, when there is too much confusion is prevailing in our minds, when there is too much corruption in the society and when the polices working is also in the questioning because of one or the other case throughout the India. It is matter of great concern that we have to thing over our administration and our practical approach because the police personals are also like us, they are part and parcel of our society and among one of us, so why we all are pin pointing towards them.
A STUDY ON TALENT MANAGEMENT AND ITS IMPACT ON EMPLOYEE RETENTION IN SELECTED...IAEME Publication
The goal of this study was to see how talent management affected employee retention in the selected IT organizations in Chennai. The fundamental issue was the difficulty to attract, hire, and retain talented personnel who perform well and the gap between supply and demand of talent acquisition and retaining them within the firms. The study's main goals were to determine the impact of talent management on employee retention in IT companies in Chennai, investigate talent management strategies that IT companies could use to improve talent acquisition, performance management, career planning and formulate retention strategies that the IT firms could use. The respondents were given a structured close-ended questionnaire with the 5 Point Likert Scale as part of the study's quantitative research design. The target population consisted of 289 IT professionals. The questionnaires were distributed and collected by the researcher directly. The Statistical Package for Social Sciences (SPSS) was used to collect and analyse the questionnaire responses. Hypotheses that were formulated for the various areas of the study were tested using a variety of statistical tests. The key findings of the study suggested that talent management had an impact on employee retention. The studies also found that there is a clear link between the implementation of talent management and retention measures. Management should provide enough training and development for employees, clarify job responsibilities, provide adequate remuneration packages, and recognise employees for exceptional performance.
ATTRITION IN THE IT INDUSTRY DURING COVID-19 PANDEMIC: LINKING EMOTIONAL INTE...IAEME Publication
Globally, Millions of dollars were spent by the organizations for employing skilled Information Technology (IT) professionals. It is costly to replace unskilled employees with IT professionals possessing technical skills and competencies that aid in interconnecting the business processes. The organization’s employment tactics were forced to alter by globalization along with technological innovations as they consistently diminish to remain lean, outsource to concentrate on core competencies along with restructuring/reallocate personnel to gather efficiency. As other jobs, organizations or professions have become reasonably more appropriate in a shifting employment landscape, the above alterations trigger both involuntary as well as voluntary turnover. The employee view on jobs is also afflicted by the COVID-19 pandemic along with the employee-driven labour market. So, having effective strategies is necessary to tackle the withdrawal rate of employees. By associating Emotional Intelligence (EI) along with Talent Management (TM) in the IT industry, the rise in attrition rate was analyzed in this study. Only 303 respondents were collected out of 350 participants to whom questionnaires were distributed. From the employees of IT organizations located in Bangalore (India), the data were congregated. A simple random sampling methodology was employed to congregate data as of the respondents. Generating the hypothesis along with testing is eventuated. The effect of EI and TM along with regression analysis between TM and EI was analyzed. The outcomes indicated that employee and Organizational Performance (OP) were elevated by effective EI along with TM.
INFLUENCE OF TALENT MANAGEMENT PRACTICES ON ORGANIZATIONAL PERFORMANCE A STUD...IAEME Publication
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Banking regulations act of India, 1949 defines banking as “acceptance of deposits for the purpose of lending or investment from the public, repayment on demand or otherwise and withdrawable through cheques, drafts order or otherwise”, the major participants of the Indian financial system are commercial banks, the financial institution encompassing term lending institutions. Investments institutions, specialized financial institution and the state level development banks, non banking financial companies (NBFC) and other market intermediaries such has the stock brokers and money lenders are among the oldest of the certain variants of NBFC and the oldest market participants. The asset quality of banks is one of the most important indicators of their financial health. The Indian banking sector has been facing severe problems of increasing Non- Performing Assets (NPAs). The NPAs growth directly and indirectly affects the quality of assets and profitability of banks. It also shows the efficiency of banks credit risk management and the recovery effectiveness. NPA do not generate any income, whereas, the bank is required to make provisions for such as assets that why is a double edge weapon. This paper outlines the concept of quality of bank loans of different types like Housing, Agriculture and MSME loans in state Haryana of selected public and private sector banks. This study is highlighting problems associated with the role of commercial bank in financing Small and Medium Scale Enterprises (SME). The overall objective of the research was to assess the effect of the financing provisions existing for the setting up and operations of MSMEs in the country and to generate recommendations for more robust financing mechanisms for successful operation of the MSMEs, in turn understanding the impact of MSME loans on financial institutions due to NPA. There are many research conducted on the topic of Non- Performing Assets (NPA) Management, concerning particular bank, comparative study of public and private banks etc. In this paper the researcher is considering the aggregate data of selected public sector and private sector banks and attempts to compare the NPA of Housing, Agriculture and MSME loans in state Haryana of public and private sector banks. The tools used in the study are average and Anova test and variance. The findings reveal that NPA is common problem for both public and private sector banks and is associated with all types of loans either that is housing loans, agriculture loans and loans to SMES. NPAs of both public and private sector banks show the increasing trend. In 2010-11 GNPA of public and private sector were at same level it was 2% but after 2010-11 it increased in many fold and at present there is GNPA in some more than 15%. It shows the dark area of Indian banking sector.
EXPERIMENTAL STUDY OF MECHANICAL AND TRIBOLOGICAL RELATION OF NYLON/BaSO4 POL...IAEME Publication
An experiment conducted in this study found that BaSO4 changed Nylon 6's mechanical properties. By changing the weight ratios, BaSO4 was used to make Nylon 6. This Researcher looked into how hard Nylon-6/BaSO4 composites are and how well they wear. Experiments were done based on Taguchi design L9. Nylon-6/BaSO4 composites can be tested for their hardness number using a Rockwell hardness testing apparatus. On Nylon/BaSO4, the wear behavior was measured by a wear monitor, pinon-disc friction by varying reinforcement, sliding speed, and sliding distance, and the microstructure of the crack surfaces was observed by SEM. This study provides significant contributions to ultimate strength by increasing BaSO4 content up to 16% in the composites, and sliding speed contributes 72.45% to the wear rate
ROLE OF SOCIAL ENTREPRENEURSHIP IN RURAL DEVELOPMENT OF INDIA - PROBLEMS AND ...IAEME Publication
The majority of the population in India lives in villages. The village is the back bone of the country. Village or rural industries play an important role in the national economy, particularly in the rural development. Developing the rural economy is one of the key indicators towards a country’s success. Whether it be the need to look after the welfare of the farmers or invest in rural infrastructure, Governments have to ensure that rural development isn’t compromised. The economic development of our country largely depends on the progress of rural areas and the standard of living of rural masses. Village or rural industries play an important role in the national economy, particularly in the rural development. Rural entrepreneurship is based on stimulating local entrepreneurial talent and the subsequent growth of indigenous enterprises. It recognizes opportunity in the rural areas and accelerates a unique blend of resources either inside or outside of agriculture. Rural entrepreneurship brings an economic value to the rural sector by creating new methods of production, new markets, new products and generate employment opportunities thereby ensuring continuous rural development. Social Entrepreneurship has the direct and primary objective of serving the society along with the earning profits. So, social entrepreneurship is different from the economic entrepreneurship as its basic objective is not to earn profits but for providing innovative solutions to meet the society needs which are not taken care by majority of the entrepreneurs as they are in the business for profit making as a sole objective. So, the Social Entrepreneurs have the huge growth potential particularly in the developing countries like India where we have huge societal disparities in terms of the financial positions of the population. Still 22 percent of the Indian population is below the poverty line and also there is disparity among the rural & urban population in terms of families living under BPL. 25.7 percent of the rural population & 13.7 percent of the urban population is under BPL which clearly shows the disparity of the poor people in the rural and urban areas. The need to develop social entrepreneurship in agriculture is dictated by a large number of social problems. Such problems include low living standards, unemployment, and social tension. The reasons that led to the emergence of the practice of social entrepreneurship are the above factors. The research problem lays upon disclosing the importance of role of social entrepreneurship in rural development of India. The paper the tendencies of social entrepreneurship in India, to present successful examples of such business for providing recommendations how to improve situation in rural areas in terms of social entrepreneurship development. Indian government has made some steps towards development of social enterprises, social entrepreneurship, and social in- novation, but a lot remains to be improved.
OPTIMAL RECONFIGURATION OF POWER DISTRIBUTION RADIAL NETWORK USING HYBRID MET...IAEME Publication
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APPLICATION OF FRUGAL APPROACH FOR PRODUCTIVITY IMPROVEMENT - A CASE STUDY OF...IAEME Publication
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DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELgerogepatton
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
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Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
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KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
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geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
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governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
2. Tejendra Patel, Ashok Parekh and Parbhubhai Tailor
http://www.iaeme.com/IJMET/index.asp 62 editor@iaeme.com
1. INTRODUCTION
At present Heating, Ventilation and Air conditioning (HVAC) industries deals with the
construction and operation of compact refrigeration system or miniature cooling system which
removes heat from limited space where high heat flux generates i.e. electronic circuit of avionics,
rocket engine nozzle, satellite electronics, turbine blade etc.As uses of electronic equipments go
on increasing day by day, there is significant attention of researchers towards the problemof heat
accumulation in an electronic circuit and miniaturization of a system. The miniature cooling
system is the only way to absorb heat by boiling of suitable working fluid and reject the same
heat to air or any secondary cooling medium to condense working fluid. The mini channel heat
exchanger reduces refrigerant charge and hence its mass. Thus condensation study in small-scale
confined space like mini channel channel is important to meet the required cooling load. The
investigation on two phase frictional pressure drop and condensing heat transfer in mini channel
during condensation becomes one of the most researched topics and also there is limited
experimental and numerical work reported in the same.
In the present situation energy saving and environmental friendly devices are the prerequisite
matter. As a consequence of the phase out of CFCs and HCFCs refrigerants due to their negative
influence on the ozone layer, HFCs came into the use but majority of them having high global
warming potential. Hence researchers are working on new HFO (Hydro fluoro olefin) refrigerants
having low GWP. The pioneer work by Sobhan and Garimella [1] focused on characterization of
heat transfer coefficient and pressure drop in era of electronics cooling application. Zhang et al.
[2] carried out research on use of refrigerant in electronic cooling and analysed the refrigerant
side condensing heat transfer coefficient for three different refrigerants R22, R410A and R407C,
flowing through circular tubes of 1.088 and 1.289 mm of hydraulic diameter. The range of mass
fluxes had been taken as 300 to 600 kg/m2
s.Pressure drop inside a horizontal mini-channel of
hydraulic diameter 0.31 mm was investigated by Lazarek and Black [3] with R113 as refrigerant.
Authors introduced Chisholm multiplier ‘C’ to calculate two-phase pressure drop. After
correlating their resultsthe value of C found to be 30. Two-phase pressure drop of H2O and air in
an adiabatic flow through capillary tubes of aluminium and glass of hydraulic diameter ranging
from 1 mm to 4 mm was studied by Mishima and Hibiki [4]. Webb and Kemal[5] studied pressure
drop during condensation in a channel of 0.44 mm hydraulic diameter. Authors first time took
the measurements in small diameter channel and it was found that the pressure drop values
increases with decrease in hydraulic diameter for a fixed value of mass flux. Cavallini et al.[6]
calculated the adiabatic pressure gradient of R134a, R236ea and R410A inside a rectangular
multi-port mini-channel tubes with hydraulic diameter of 1.4 mm. Correlations developed by
Friedel [7], Zhang and Webb [14], Mishima and Hibiki [4] and Müller-Steinhagen and Heck[8]
were used in their study and are in good agreement with experimental data. Pressure drop during
condensation within single circular 0.96 mm diameter mini channel using R1234yf was
investigated by Del Col et al.[9] and then it was compared with R134a results[13]. It was found
that the values of pressure drop using R1234yf was lower than R134a values by 10 to 12 % under
the similar conditions and It was concluded that R1234yf performance is better than R134a.
Bohdal et al.[10]studied pressure drop during condensation of R404A and R134a inside mini-
channel. Authors showed that the pressure drop values can be accurately estimated by correlations
of Friedel [7] and Garimella [12]. Authors also developed a new correlation for pressure drop
calculations. The literature studies reveal that there is no accurate method to predict the two phase
frictional pressure drop. In the present study broad experimental results have been taken from
open literature and these results have been compared with the results of various frictional pressure
drop models. Based on this comparison Kim and Mudawar [19] model having minimum MRD
and MARD have been found. With correction in constants of Kim and Mudawar [19] model, the
3. Theoretical Analysis of Two-Phase Frictional Pressure Drop during Condensing in Horizontal Mini
Channel
http://www.iaeme.com/IJMET/index.asp 63 editor@iaeme.com
new model with lower value of MRD and MARD has been developed to predict two phase
frictional pressure drop.
2. COMPARATIVE STUDIES OF VARIOUS TWO PHASE FRICTIONAL
PRESSURE DROP MODELS
During condensation process in mini channel the friction is main reason for pressure drop and
term two phase frictional multiplier ( ) is used to find two phase frictional pressure drop. In
present study total 454 experimental results are obtained from research work of Na Liu et al. [15],
A. F.Illan-Gomez at al [17], Alejandro López-Belchí et al. [18] , and Chang-Hyo Son et al. [16].
The experimental results of two phase frictional pressure drop covers horizontal mini channel of
hydraulic diameter 0.952 mm, 1.152 mm, 1mm& 1.034 mm, Saturation temperature such as 30
0
C, 40 0
C, 45 0
C, and 500
C and refrigerants R290, R1234yf, R1234ze, R22, R32, R410A, R134a
and R152a. These experimental results of two phase frictional pressure drop have been compared
with results obtained from various models as shown table 1. To obtain two phase frictional
pressure drop the thermo-physical properties of refrigerants, non-dimensional numbers,
geometrical parameters and constants are evaluated. The MRD (Mean Relative Deviation) and
MARD (Mean Absolute Relative Deviation) have been evaluated for all eight models under
consideration. The eight models under consideration are Del col et al. [82], the Kim & Mudwar
[19], the Mishima & Hibiki [4], the Cavallini et al. [6], Trans et al. [20], Zhang & Web [14],
Friedel et al.[11] and Garimella et al. [12]. The comparison shows that Kim and Mudawar [19]
model has best predictability of experimental data with an MRD of -7.36 % & MARD of 12.21%.
This model is taken as reference model to develop a new correlation. Table 2 shows the sources
of results which are taken from the open literature along with their test condition for this present
study.
Table 1 Asummary of the two-phase frictional pressure gradient correlations using two-phase multiplier.
Authors Remarks Equations
Friedel et
al. [11]
D > 4 mm, air–
water,
refrigerants,
developed
from 25,000
data points
= = +
.
. ∙ .
,
= − + ∙
!" ∙ #$
!$ ∙ #
%
& = '(.)*
∙ 1 − ' (.,,-
, . =
/0
/1
%
(.23
∙ 4
51
50
6
(.32
∙ 41 −
51
50
6,
Cavallini
et al. [6]
D=0.96 mm,
Condensation,
R1234ze, R22,
R32
According to Cavallini et al pressure gradient in mini-channels is
given by
78
79 :;
= ∅0=
, 78
79 0=
,Where,
78
79 0=
=
,>?@AB
CD?
; E0= = 0.046IJ0=
K(.,
Two phase multiplier is given by:
∅0=
,
= L + 3.595&. 1 − P Q
; R = 1.398 UV
L = 1 − ' ,
+ ',
/0
/1
% 41 −
51
50
6
W.X-,
& = '(.2X,X
1 − ' (.-3-
. =
/0
/1
%
3.3W,
4
51
50
6
(.--
41 −
51
50
6
W.X-,
E=Entrainment fraction
4. Tejendra Patel, Ashok Parekh and Parbhubhai Tailor
http://www.iaeme.com/IJMET/index.asp 64 editor@iaeme.com
P = 0.015 + 0.44 log
D]^
D?
_?`]
a
,
∗ 10-
c ; P < 0.95, P =
0.95 ; P ≥ 0.95, g1
∗
=
Ah
iC1D]jD?KD]k
; dimensionless gas velocity
/1l = /1 m1 +
1 − ' P
'
%n
Garimella
et al.[1]
D=0:5 -
4:91mm,
condensation,
R134a
To calculate total pressure drop through mini-channels, first void
fraction using Baroczy’s correlation is to be calculated:
∈= p1 + 4
1 − '
'
6
(.)-
4
/1
/0
6
(.qX 50
51
%
(.3W
r
K3
Total pressure drop is given by:
4
st
sL
6
:;
=
1
2
Ev
w,
',
/1 ∈,.X
1
x
Where, Ev= interface friction factor, calculated as
Ev
E0
= yz{
IJ0
|
}l
Laminar region IJ0 < 2100 : y = 1.308 ∗ 10KW
; • = 0.427; • =
0.93; ‚ = −0.121
Turbulent region IJ0 > 2100 : y = 25.64;• = 0.532;• =
−0.327; ‚ = 0.121
Surface tension parameter is evaluated as
} =
g050
„
g0 =
A 3Kh
D? 3K∈
; superficial velocity
And X= Martinelli parameter, calculated as
z = m
st sL⁄ 0
st sL⁄ 1
n
3 ,⁄
Mishima
and
Hibiki [4]
D = 1.05 -4.08
mm,
adiabatic, air-
water
4
st
sL
6
†8
= 1 +
‡
z
+
1
z,
; Eˆ‰‰J‚Š•‹Œ•Ž•‰‚ℎ•‹‹JŽ,
‡ = 21 ∙ •1 − J'U ∙ 4−
0.319
x‘
6’ ; x‘“””•, Eˆ‰‚–‰‚•Ž•‰Š••J, ‡
= 21 ∙ 1 − J'U ∙ 4−
0.333
x
6% ; x“””•
Zhang and
Webb [14]
D = 0.06 mm,
water Re
<2000
‡ = 21 ∙ 41 − exp 4−
0.358
‡ˆ‹
66
Tran et al.
[20]
Circular
channels with
D = 2.46 and
2.92 mm,
rectangular
š›œ
,
= 1 + 4.3z:: − 1 “‡ˆ‹ 1 − ' (.*)X
+ '3.)X• 4
st
sL
6
†8
= 4
st
sL
6
›œ
š›œ
,
Zhang and
Webb [14]
D = 3.25 and
6.25 mm,
multiport
extruded Al
channels with
Dh = 2.13 mm,
š›œ
,
= 1 − ' ,
2.87',
4
t•{:
tlVv:
6
K3
, tVž7 = 4
t•{:
tlVv:
6 , 4
st
sL
6
†8
= 4
st
sL
6
›œ
š›œ
,
5. Theoretical Analysis of Two-Phase Frictional Pressure Drop during Condensing in Horizontal Mini
Channel
http://www.iaeme.com/IJMET/index.asp 65 editor@iaeme.com
adiabatic,
R134a,
R22,R404A
Del Col et
al. [9]
D = 8 mm,
horizontal
tubes, R22,
R134a, R125,
R32, R236ea,
R407C,
R410A
7;
7Ÿ †8 =
78
79 ›œ
š›œ
,
, š›œ
,
= P +
3.,q, ¡¢
Qž£.¤¥¦§ , &¡
= '(.q*)*
, . =
4
D?
D]
6
(.W,)*
∙
_]
_?
K3.33*
∙ 1 −
_]
_?
W.-))
, P = 1 − ' ,
',
∙ 4
D?∙>]
D]∙>¤
6,
E0 = 8 “
*
¨ž?
3,
+ {“2457Ž‹
¨ž?
)
(.2
•3q
+
W)XW(
¨ž?
3q
}K3.X
•3/3,
,
E1 = 8 “
8
IJ1
%
3,
+ {“2457Ž‹ 4
IJ1
7
6
(.2
•3q
+
37530
IJ1
%
3q
}K3.X
•3/3,
RJ =
w,
x
/„
Kim and
Mudawar
[19]
D = 0.0695 -
6.22 mm,
adiabatic,
condensing,
developed
from
database
ɸ›
,
= 1 +
-
®
+
3
®B, ‡ = •IJ0=
|
¯•1=
l
4
D?
D]
6
7
, ¯•1=
l
=
D]aC°
_]
B
a, b, c, and d are constants by Kim and Mudawar.22
Table 2 Details of data source and its experimental parameters
Sr.
No.
DataSources Working Fluid
Parameters Range
(Hydraulic diameter/Saturation temperature/Mass flux/Vapour
quality/cross section of channel)
1
Alejandro López-Belchí et
al.
NaLiu,HangXiao,Junming
Li et al.
R290
1.08mm/40 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/circular & Square
single
2
Alejandro López-Belchí et
al. and F.Gomez, A. L
opez, J.R.Garcı´a, et al.
R1234yf
1.16 mm/30 0
C to 55 0
C/350-640 kg/m2
s/0.39-0.89/ Square multi-
port
3
NaLiu,Hang
Xiao,JunmingLi, et al.
R1234ze
1.08mm/40 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/circular & Square
single
4
Alejandro López-Belchí et
al., et al.
R134a
1.16 mm/40 0
C to 50 0
C/300-800 kg/m2
s/0.1-0.9/circular & Square
single
5
Chang-Hyo Son et al.
Na Liu, Junming Li et al.
2015 et al.
R22
1.152 mm/30 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/Circular
0.952 mm/30 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/Square
1.304mm/30 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/Square
6 Na Liu, Junming Li et al. R32
1.152 mm/30 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/Circular
0.952 mm/30 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/Square
1.304mm/30 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/Square
7
Alejandro López-Belchí et
al.
Na Liu, Junming
Li et al.
R152a
1.152 mm/30 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/Circular
0.952 mm/30 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/Square
1.304mm/30 0
C to 50 0
C/200-800 kg/m2
s/0.1-0.9/Square
±Ix =
3
²
∑
7;/7Ÿ v ^´?K7;/7Ÿ v µ¶·
7;/7Ÿ v µ¶·
²
v¸3 (1)
±yIx =
3
²
∑ ¹
7;/7Ÿ v ^´?K7;/7Ÿ v µ¶·
7;/7Ÿ v µ¶·
¹²
v¸3 (2)
6. Tejendra Patel, Ashok Parekh and Parbhubhai Tailor
http://www.iaeme.com/IJMET/index.asp 66 editor@iaeme.com
Where, (dp/dz)cal is the calculated value, (dp/dz)exp is the experimental value, and N is the
number of data points.Table 3 Comparison between experimental data and correlation prediction
for flow through mini-channels
S
r.
N
o
.
Data
Source
s
Wo
rkin
g
Flui
d
% Error of Authors models
Cavalli
ni et
al.
Fri
ede
l et
al.
Wh
ang
&
Ki
m
et
al.
Garime
lla et
al.
Del
cole et
al.
Kim &
Mudawar
et al.
Tran
s et
al.
Zh
an
g
&
W
eb
et
al.
New
Corr
elatio
n
1
Na
Liu,
Hang
Xiao,J
unmin
g Li,
2016
R29
0
M
RD
-21.54
-
21.
30
54.
70
-50.44 -15.11 -8.33
-
65.3
15
-
52.
29
-0.61
M
AR
D
22.027
23.
046
9
55.
67
-50.44 17.75 10.7087
81.2
1
63.
00
9.054
2
F.Gom
ez, A.
L
opez,
J.R.
Garcı´
a,(201
5)
R12
34y
f
M
RD
-12.34
-
46.
92
77.
58
-38.08 -12.22 13.93 -5.47
-
38.
08
2
24.90
M
AR
D
20.58
46.
92
108
.07
6
67.09 20.58 41.04
140.
9
67.
09
3
48.86
3
Na
Liu,
Hang
Xiao,J
unmin
g Li,
2016
R12
34z
e
M
RD
-2.08
-
29.
864
40.
06
61.83 -12.86 -13.608
-
83.7
7
-
47.
24
-7.95
M
AR
D
8.70
30.
23
40.
065
61.83 22.30 21.94
83.7
7
66.
48
9
19.64
4
Na
Liu,
Junmi
ng Li
et al.
2015
# 1
SQUA
RE
R22
M
RD
-14.40
-
11.
877
178
.22
-34.65 -15.29 -7.41
-
76.9
16
-
51.
08
8
1.03
M
AR
D
15.78
23.
092
178
.22
39.083 18.96 8.39
79.0
56
63.
66
6.329
5
Na
Liu,
Junmi
ng Li
R32
M
RD
-34.63
-
9.3
61
157
.72
-40.68 -39.78 -9.313
-
29.4
2
-
48.
50
8
-
0.981
7. Theoretical Analysis of Two-Phase Frictional Pressure Drop during Condensing in Horizontal Mini
Channel
http://www.iaeme.com/IJMET/index.asp 67 editor@iaeme.com
et al.
2015
1 #
Square
M
AR
D
35.53
22.
908
6
157
.72
41.13 40.36 10.734
98.5
4
71.
50
8
8.239
6
Na Liu
&
Junmi
ng
Li et
al.
2015
R15
2a
M
RD
6.369
-
28.
175
31.
23
-
60.521
-
13.975
-9.207
84.2
73
-
49.
67
3
-1.32
M
AR
D
13.428
29.
725
31.
31
-
60.521
18.058 9.207
85.9
82
70.
28
5
3.22
7
Alejan
dro
López-
Belchí
et
al.,201
6
R13
4a
M
RD
38.568
5.4
01
222
.60
-1.59 36.589 35.35
-
76.1
6
-
31.
72
5
-
27.68
M
AR
D
83.731
62.
381
241
.43
83.854 79.99 88.287
85.9
6
86.
23
2
55.31
2
8
Alejan
dro
López-
Belchí
et
al.,201
6
R41
0A
M
RD
35.986
-
10.
849
215
.68
5
-
41.274
-
38.440
-9.899
-
68.9
45
-
66.
58
0
-
2.091
M
AR
D
35.986
18.
399
215
.68
5
41.274 38.440 10.699
72.3
59
68.
06
7
6.393
Average
M
RD
-
20.901
-
17.
945
120
.01
3
-43.54 -26.03 -7.73
-
55.5
9
-
50.
85
1
-
0.000
165
M
AR
D
24.73
24.
737
121
.97
46.58 29.41 12.33
89.2
46
67.
45
4
10.08
33
3. RESULT AND DISCUSSION
Comparative assessment of eight available different Frictional pressure gradient models has been
carried out and evaluated Mean Relative Deviation (MAD) and MARD (Mean Absolute Relative
Deviation) of each correlation. Finally doing so the correlation which is having minimum error
based on new constant value which deals concern fluid properties and non-dimensional number.
Table 3 indicates the MAD and MARD of all eight models under consideration in the present
study. After comparison it has been found in fig that in case of frictional pressure gradient for
refrigerant flow through horizontal mini-channels, the Kim & Mudawar et al. model has the
considerable predictability of experimental data with an MRD of -7.73 % & MARD of 12.33%.
There are also Cavallini et al. and Freidel et al. models showing good agreement with MARD of
24.11% & 24.74% respectively. It shows good integrity of Kim & Mudawar et al. model with
experimental data compared to other model whereas Cavallini et al. and Freidel et al. correlations
are showing comparatively less integrity than the Kim & Mudawar et al. Among all correlation
except these three Kim & Mudawar et al., Cavallini et al. and Freidel et al correlation other are
under predicting the experimental frictional pressure gradient data. Whang & Kim et al.
correlation is over predicting the experimental data. Now based on above comparison model with
low MRD and MARD has been taken as reference and develop new model by taking new constant
value and ratio of non-dimensional number which are concern to physical properties of working
9. Theoretical Analysis of Two-Phase Frictional Pressure Drop during Condensing in Horizontal Mini
Channel
http://www.iaeme.com/IJMET/index.asp 69 editor@iaeme.com
(g) (h)
Fig. 1 Comparison of Result of experimental Frictional Pressure Gradient with predicted Frictional
Pressure Gradient of (a) Wang & Kim et al. (b) Frediel et al. (c) Zhang & Webb et al. (d) Trans et al. (e)
Del cole et al. (f) Garimella (g) Kim & Mudwar et al. (h) Cavallini et al model.
So finally new modified correlation has been developed with minimum MRD -0.000165 %
and MARD 10.08 % by introducing some new constants and non-dimensional number in existing
low MARD correlation. New modified correlation,
ɸ²žº
,
= 1 +
-
®
+
3
®B
, ‡²žº = 0.3572IJ0=
(.(X(,3
¯•1=
(.(22
&(.(,X
.(.(3X
, ¯•1=
l
=
D]aC°
_]
B ,
7;
7Ÿ †8 =
78
79 ›
š›
,
(3)
Figure 2 Comparison of Result of experimental Frictional Pressure Gradient with predicted Frictional
Pressure Gradient of New model.
New developed correlation is suitable for refrigerants R290, R1234yf, R1234ze, R22, R410A
and R32 for the saturation temperature range 30 to 50 0
C. It is also applicable for hydraulic
diameter range from 0.952 mm to 1.150 mm horizontal mini channel. Fig 1 shows the comparison
10. Tejendra Patel, Ashok Parekh and Parbhubhai Tailor
http://www.iaeme.com/IJMET/index.asp 70 editor@iaeme.com
made between literature experimental data [15, 16, 17, and 18] and all eight Frictional pressure
gradient model or correlation along with new developed correlation and showing the integrity of
experimental data with model. It can be seen from the table 3 and Fig. 1 except kim & Mudawar,
Freidel et al. and cavallini et al. model all correlation not fairly match and not fit under the ±30
% deviation with the experimental data [15,16,17,18]. Fig. 2 shows good integrity between
predicted data and experimental data [15, 16, 17, and 18] within ±15 % deviation.
4. CONCLUSION
Comparative analysis has been carried out for condensing frictional pressure drop by taking
experimental resuts of the various researches [15, 16, 17, and 18] and total eight models have
been reviewed. Kim and Mudawar model is showing good agreement with MRD of -7.73 %&
MARD of 12.33%.There are also Cavallini et al. and Freidel et al models showing agreement
with MRD of -24.73 % &24.13% respectively. From compiled experimental results of various
researchers new modified model has been developed for frictional pressure drop with MRD-
0.000165 % and MARD 10.033 %.
REFERENCES
1. Sobhan, S.V. Garimella, A comparative analysis of studies on heat transfer and fluid flow in
microchannels, Microscale Thermo phys. Eng. 5293–311. (2001) .
2. H.Y. Zhang, J.M. Li, N. Liu, and B.X. Wang, Experimental investigation of condensation heat
transfer and pressure drop of R22, R410A and R407C in mini-tubes, International Journal of
Heat and Mass Transfer, 55 3522-3532. (2012).
3. G. M. Lazarek and S. H. Black, “Evaporative heat transfer, pressure drop and critical heat flux
in a small vertical tube with R-113,” Int. J. Heat Mass Transf., vol. 25, no. 7, pp. 945–960, 1982.
4. K. Mishima and T. Hibiki, “Some characteristics of air-water two-phase flow in small diameter
vertical tubes,” Int. J. Multiph. Flow, vol. 22, no. 4, pp. 703–712, 1996.
5. R. L. Webb and K. Ermis, “Effect of Hydraulic Diameter on Condensation of R-134A in Flat,
Extruded Aluminum Tubes,” J. Enhanc. Heat Transf., vol. 8, no. 2, pp. 77–90, 2001.
6. Cavallini, D. Del Col, L. Doretti, M. Matkovic, L. Rossetto, and C. Zilio, “Two-phase frictional
pressure gradient of R236ea, R134a and R410A inside multi-port mini-channels,” Exp. Therm.
Fluid Sci., vol. 29, no. 7 SPEC. ISS., pp. 861–870, 2005.
7. L. Friedel, “Improved friction pressure drop correlations for horizontal and vertical two phase
pipe flow,” in European Two-Phase Flow Group Meeting, 1979, vol. 18, July, pp. 485–491.
8. H. Muller-Steinhagen and K. Heck, “A simple friction pressure drop correlation for two-phase
flow in pipes,” Chem. Eng. Process., vol. 20, no. 6, pp. 297–308, 1986.
9. D. Del Col, D. Torresin, and A. Cavallini, “Heat transfer and pressure drop during condensation
of the low GWP refrigerant R1234yf,” Int. J. Refrig., vol. 33, no. 7, pp. 1307–1318, 2010.
10. T. Bohdal, H. Charun, and M. Sikora, “Comparative investigations of the condensation of R134a
and R404A refrigerants in pipe minichannels,” Int. J. Heat Mass Transf., vol. 54, no. 9–10, pp.
1963–1974, 2011.
11. L. Friedel, “Improved friction pressure drop correlations for horizontal and vertical two phase
pipe flow,” in European Two-Phase Flow Group Meeting, 1979, vol. 18, July, pp. 485–491.
12. S. GARIMELLA, A. AGARWAL, and J. D. KILLION, “Condensation Pressure Drop in
Circular Microchannels,” Heat Transf. Eng., vol. 26, no. 3, pp. 28–35, 2005.
13. Cavallini, D. Del Col, M. Matkovic, and L. Rossetto, “Pressure Drop During Two-Phase Flow
of R134a and R32 in a Single Minichannel,” J. Heat Transfer, vol. 131, no. 3, p. 33107, 2009.
14. M. Zhang and R. L. Webb, “Correlation of two-phase friction for refrigerants in small-diameter
tubes,” Exp. Therm. Fluid Sci., vol. 25, no. 3–4, pp. 131–139, 2001.
11. Theoretical Analysis of Two-Phase Frictional Pressure Drop during Condensing in Horizontal Mini
Channel
http://www.iaeme.com/IJMET/index.asp 71 editor@iaeme.com
15. Na Liu, Junming Li , Experimental study on pressure drop of R32, R152a and R22 during
condensation in horizontal minichannels, Experimental Thermal and Fluid Science 71 (2016)
14–24.
16. Daniel Felipe Sempértegui-Tapia, Gherhardt Ribatski, Two-phase frictional pressure drop in
horizontal micro-scale channels: experimental data analysis and prediction method
development, International Journal of Refrigeration (2017) Accepted manuscript.
17. Fronk, B. M., Garimella, S. Measurement of heat transfer and pressure drop during condensation
of carbon dioxide in microscale geometries. Proceedings of 2010 14th International Heat
Transfer Conference (IHTC14), IHTC14-22987, Volume 2/Condensation, pp. 235-243, August
8-13, 2010, Washington, DC, USA, 2010.
18. F. Illan-Gomez, A. Lopez-Belchi, J.R. Garcia-Cascales, F. Vera-Garcia, Experimental two-
phase heat transfer coefficient and frictional pressure drop inside mini-channels during
condensation with R1234yf and R134a, International Journal of Refrigeration, (2014).
19. S. M. Kim and I. Mudawar, Review of databases and predictive methods for pressure drop in
adiabatic, condensing and boiling mini/micro-channel fows, Int. J. Heat Mass Transfer 77 (2014)
74–97.
20. T. N. Tran, M. C. Chyu, M. W. Wambsganss and D. M. France, Two-phase pressure drop of
refrigerants during °ow boiling in small channels: An experimental investigation and correlation
development, Int. J. Multiphase flow 26 (2000) 1739–1754.
21. Lockhart RW, Martinelli RC (1949) Proposed correlation of data for isothermal two-phase, two-
component flow in pipes. ChemEng Prog 45:39–48.
22. D. Chisholm, A.D.K. Laird, Two phase flow in rough tubes, ASME Trans. 80 (2) (1958) 227–
276.
23. M. Souza and M. M. Pimenta, Prediction of pressure drop during horizontal two-phase flow of
pure and mixed refrigerants, ASME Cavi. Multiphase Flow 210 (1995) 161–171.
24. L. Sun and K. Mishima, Evaluation analysis of prediction methods for two-phase °ow pressure
drop in mini-channels, Int. J. Multiphase Flow 28 (2002) 927–941.
25. S. Lin, C. C. K. Kwok, R. Y. Li, Z. H. Chen and Z. Y. Chen, Local frictional pressure drop
during vaporization of R-12 through capillary tubes, Int. J. Multiphase Flow 17 (1991) 95–102.
26. L. S. Kim, K. D. Son, D. Saker, J. H. Jeong and S. H. Lee, An assessment of models for
predicting refrigerant characteristics in adiabatic and non-adiabatic capillary tubes, Heat Mass
Transfer 47 (2011) 163–180.
27. Chen IY, Yang KS, Chang YJ, Wang CC (2001) Two-phase pressure drop of air-water and R-
410a in small horizontal tubes. Int J Multiph Flow 27:1293–1299.