IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Numerical Simulations on Jet Impingement Cooling of Cylindrical SurfacesIRJET Journal
This document summarizes a numerical study on jet impingement cooling of cylindrical surfaces. Jet impingement exhibits non-uniform heat transfer on cylinders, with maximum heat transfer at the jet stagnation zone and local maxima/minima occurring along the circumference due to transition between laminar and turbulent flow. Parameters studied include jet Reynolds number and cylinder to jet diameter ratio. Results for smooth cylinders matched literature. Heat transfer decreases with Reynolds number from 100 to 1000 but increases beyond 1000. The study aims to address gaps in understanding jet impingement cooling effects on cylinders.
Heat Transfer Enhancement through Liquid Jet ImpingementIRJET Journal
This document provides a literature review on experimental and computational studies of liquid jet impingement heat transfer. It summarizes various parameters that influence jet impingement heat transfer such as flow rate, nozzle size, inlet pressure, and working medium properties. It then reviews over 30 experimental and computational studies on topics like the effects of nozzle geometry, surface roughness, nanofluids, vortex generators, swirling jets, and more. The overall goal is to provide an overview of recent approaches to studying jet impingement heat transfer processes.
Vortex Tube Usage in Cooling and Liquification Process of Excess Gases in Ghe...Samet Baykul
DATE: 2019.05
- Computational analysis of a vortex tube
- Developing boundary conditions for heat transfer analysis
- CAD by creating a suitable model for heat transfer analysis
- CFD analysis by using ANSYS FLUENT
- Literature survey for recent academic studies
ABSTRACT:
Vortex tubes are simple and common devices which separates a high-pressure gas flow as two different lower gas flows. One of the outlets has a higher temperature than the inlet high pressure gas and other outlet has lower. Most common types of the vortex tubes are counter and parallel flow types. In counter flow type vortex tubes the cold and hot outlets are on opposite sides and in parallel flow type both the outlets are on the same side. Since it is a simple, well known, compact, portable, highly reliable and has a few initial costs, it could be desirable for the specific heating or cooling and refrigeration applications.
IRJET- Study of Jet Impingement Heat TransferIRJET Journal
This document reviews research on jet impingement heat transfer. It discusses the flow and heat transfer characteristics of single and multiple impinging jets. Key factors that influence heat transfer are jet Reynolds number, nozzle-to-plate spacing, jet pattern, and crossflow. The document summarizes various empirical correlations that have been developed to predict average heat transfer coefficients. It also reviews numerical studies on modeling heat transfer for multi-jet systems and discusses the effects of parameters like Reynolds number, nozzle spacing, crossflow, and jet interference.
Computational Analysis of Turbulent flow heat transfer and pressure loss in D...IRJET Journal
This document discusses computational analysis of turbulent flow, heat transfer, and pressure loss in ducts or pipes with segmental baffles. Segmental baffles are implemented to enhance flow characteristics and thermal performance. Due to the baffles, significant turbulence is generated, increasing friction with the pipe and improving heat transfer but also leading to greater pressure drop. Finite element analysis is conducted using ANSYS Fluent to simulate turbulent flow over a range of Reynolds numbers in smooth and baffled pipes. Results are validated against published experimental and numerical data and show good agreement. Contour plots illustrate increased turbulence and velocity magnitude in baffled pipes compared to smooth pipes.
The document summarizes an experimental and computational fluid dynamics (CFD) analysis of a vortex tube. A vortex tube produces hot and cold air streams from a single source of compressed air without any moving parts. The study examined a vortex tube made of CPVC material, which is cheaper and lighter than metals typically used. CFD simulations were conducted to model the vortex tube. While various theories have been proposed, the temperature separation phenomenon in vortex tubes is not fully understood due to the complex turbulence inside the device. Parameters like inlet pressure and orifice diameter were analyzed to understand their effects on the performance.
A Review on Comparison between Shell And Tube Heat Exchanger And Helical Coil...ijiert bestjournal
The curved shape of the tube causes the flowing fluid to experience centrifugal force. The
extent of centrifugal force experienced depends on the local axial velocity of the fluid particle
and radius of curvature of the coil. The fluid particles flowing at the core of the pipe have
higher velocities than those flowing near to the pipe wall. Thus the fluid particles flowing
close to the tube wall experience a lower centrifugal force than the fluid particles flowing in
the tube core. This causes the fluid from the core region to be pushed towards the outer wall.
This stream bifurcates at the wall and drives the fluid towards the inner wall along the tube
periphery, causing generation of counter-rotating vortices called secondary flows which
produce additional transport of the fluid over the cross section of the pipe. This additional
convective transport increases heat transfer and the pressure drop when compared to that in a
straight tube.
3 ijaems jun-2015-17-comparative pressure drop in laminar and turbulent flowsINFOGAIN PUBLICATION
This document summarizes a study that uses computational fluid dynamics (CFD) to analyze laminar and turbulent flows in circular pipes with and without baffles. It presents the following key points:
1) CFD simulations were conducted using ANSYS Fluent to analyze pressure drop and hydrodynamic performance in smooth and segmented baffle pipes across a range of Reynolds numbers in laminar and turbulent flow regimes.
2) The CFD results were validated by comparing to published experimental and analytical results, showing good agreement.
3) Introducing baffles into the pipe was found to increase turbulence, friction, and pressure drop compared to a smooth pipe, as expected based on prior studies of baffled pipes
Numerical Simulations on Jet Impingement Cooling of Cylindrical SurfacesIRJET Journal
This document summarizes a numerical study on jet impingement cooling of cylindrical surfaces. Jet impingement exhibits non-uniform heat transfer on cylinders, with maximum heat transfer at the jet stagnation zone and local maxima/minima occurring along the circumference due to transition between laminar and turbulent flow. Parameters studied include jet Reynolds number and cylinder to jet diameter ratio. Results for smooth cylinders matched literature. Heat transfer decreases with Reynolds number from 100 to 1000 but increases beyond 1000. The study aims to address gaps in understanding jet impingement cooling effects on cylinders.
Heat Transfer Enhancement through Liquid Jet ImpingementIRJET Journal
This document provides a literature review on experimental and computational studies of liquid jet impingement heat transfer. It summarizes various parameters that influence jet impingement heat transfer such as flow rate, nozzle size, inlet pressure, and working medium properties. It then reviews over 30 experimental and computational studies on topics like the effects of nozzle geometry, surface roughness, nanofluids, vortex generators, swirling jets, and more. The overall goal is to provide an overview of recent approaches to studying jet impingement heat transfer processes.
Vortex Tube Usage in Cooling and Liquification Process of Excess Gases in Ghe...Samet Baykul
DATE: 2019.05
- Computational analysis of a vortex tube
- Developing boundary conditions for heat transfer analysis
- CAD by creating a suitable model for heat transfer analysis
- CFD analysis by using ANSYS FLUENT
- Literature survey for recent academic studies
ABSTRACT:
Vortex tubes are simple and common devices which separates a high-pressure gas flow as two different lower gas flows. One of the outlets has a higher temperature than the inlet high pressure gas and other outlet has lower. Most common types of the vortex tubes are counter and parallel flow types. In counter flow type vortex tubes the cold and hot outlets are on opposite sides and in parallel flow type both the outlets are on the same side. Since it is a simple, well known, compact, portable, highly reliable and has a few initial costs, it could be desirable for the specific heating or cooling and refrigeration applications.
IRJET- Study of Jet Impingement Heat TransferIRJET Journal
This document reviews research on jet impingement heat transfer. It discusses the flow and heat transfer characteristics of single and multiple impinging jets. Key factors that influence heat transfer are jet Reynolds number, nozzle-to-plate spacing, jet pattern, and crossflow. The document summarizes various empirical correlations that have been developed to predict average heat transfer coefficients. It also reviews numerical studies on modeling heat transfer for multi-jet systems and discusses the effects of parameters like Reynolds number, nozzle spacing, crossflow, and jet interference.
Computational Analysis of Turbulent flow heat transfer and pressure loss in D...IRJET Journal
This document discusses computational analysis of turbulent flow, heat transfer, and pressure loss in ducts or pipes with segmental baffles. Segmental baffles are implemented to enhance flow characteristics and thermal performance. Due to the baffles, significant turbulence is generated, increasing friction with the pipe and improving heat transfer but also leading to greater pressure drop. Finite element analysis is conducted using ANSYS Fluent to simulate turbulent flow over a range of Reynolds numbers in smooth and baffled pipes. Results are validated against published experimental and numerical data and show good agreement. Contour plots illustrate increased turbulence and velocity magnitude in baffled pipes compared to smooth pipes.
The document summarizes an experimental and computational fluid dynamics (CFD) analysis of a vortex tube. A vortex tube produces hot and cold air streams from a single source of compressed air without any moving parts. The study examined a vortex tube made of CPVC material, which is cheaper and lighter than metals typically used. CFD simulations were conducted to model the vortex tube. While various theories have been proposed, the temperature separation phenomenon in vortex tubes is not fully understood due to the complex turbulence inside the device. Parameters like inlet pressure and orifice diameter were analyzed to understand their effects on the performance.
A Review on Comparison between Shell And Tube Heat Exchanger And Helical Coil...ijiert bestjournal
The curved shape of the tube causes the flowing fluid to experience centrifugal force. The
extent of centrifugal force experienced depends on the local axial velocity of the fluid particle
and radius of curvature of the coil. The fluid particles flowing at the core of the pipe have
higher velocities than those flowing near to the pipe wall. Thus the fluid particles flowing
close to the tube wall experience a lower centrifugal force than the fluid particles flowing in
the tube core. This causes the fluid from the core region to be pushed towards the outer wall.
This stream bifurcates at the wall and drives the fluid towards the inner wall along the tube
periphery, causing generation of counter-rotating vortices called secondary flows which
produce additional transport of the fluid over the cross section of the pipe. This additional
convective transport increases heat transfer and the pressure drop when compared to that in a
straight tube.
3 ijaems jun-2015-17-comparative pressure drop in laminar and turbulent flowsINFOGAIN PUBLICATION
This document summarizes a study that uses computational fluid dynamics (CFD) to analyze laminar and turbulent flows in circular pipes with and without baffles. It presents the following key points:
1) CFD simulations were conducted using ANSYS Fluent to analyze pressure drop and hydrodynamic performance in smooth and segmented baffle pipes across a range of Reynolds numbers in laminar and turbulent flow regimes.
2) The CFD results were validated by comparing to published experimental and analytical results, showing good agreement.
3) Introducing baffles into the pipe was found to increase turbulence, friction, and pressure drop compared to a smooth pipe, as expected based on prior studies of baffled pipes
Hydrodynamic study of anadjustableheightpacked column operatingIAEME Publication
This document summarizes a study on the hydrodynamic performance of an adjustable height packed column operating on the principle of an air lift pump. The column is packed with glass rings and operates in a closed water loop with air injection at the base. Water flow rates, pressure drop, gas holdup, and efficiency were measured for different air flow rates and submersion depths. The results show that water flow rate increases with air flow rate and submersion depth. Pressure drop follows a second order polynomial relationship with submersion depth. Gas holdup also increases with air flow rate and decreases with water flow rate. The system provides good mixing with low power consumption and could be used for applications involving heat and mass transfer.
Effect on heat transfer for laminar flow over Backward Facing Step with squar...ijceronline
The purpose of this paper is to study the influence of an adiabatic square cylinder on the heat transfer enhancement in the 2D laminar flow over the Backward Facing Step (BFS). This work also studies the effect of streamwise position of the square cylinder on heat transfer enhancement. The governing equations, for the 2D laminar flow over BFS with a square cylinder placed inside, are solved on nonuniform Cartesian grid using projection method. The individual differential terms of the N-S equations are discretized using a Higher Order Compact Scheme (HOCS). The numerical code is first validated with the results available in the literature. The main advantage of HOCS is to obtain higher order approximations to the derivatives accurately without the necessity of higher number of nodes. Thus reducing the computational cost. It is observed from the numerical experiment that placing the cylinder affects the fluid flow and heat transfer and for XC=1.4, YC = 1.0 and Re= 200, there is a maximum heat transfer enhancement of 193.93%.The results of these numerical experiments are useful in studying the heat transfer enhancement and its dependence on the bluff body and flow characteristics. This work has its applications in engineering problems where the heat transfer in a laminar flow regime can be enhanced using a bluff body. The current work also demonstrates the dependence of horizontal position of cylinder on heat transfer augmentation.
This document summarizes a numerical study of turbulent flow downstream from a linear heat source placed inside the cylinder wake. The study used computational fluid dynamics (CFD) to model the flow and heat transfer at varying Reynolds numbers. The k-ε realizable turbulence model was applied. Results showed that instabilities in the wake zone increase with Reynolds number, forming a von Karman vortex street that influences the thermal field and diffusion process. Comparisons of numerical results to experimental data were satisfactory. The study provides insight into how wake structures impact heat transport and scalar diffusion in turbulent flows.
New Microsoft Office PowerPoint PresentationSudhir Shinde
This document summarizes a seminar presentation on heat transfer via jet impingement. The presentation discusses how jet impingement is used to effectively remove large amounts of heat from surfaces, such as in cooling turbine blades and electronics. It reviews factors that influence heat transfer, including nozzle diameter, jet-to-surface spacing, and Reynolds number. The experimental setup examines heat transfer characteristics of air and water jets impinging on a heated surface. Results show that lower jet diameters and spacings and higher Reynolds numbers increase heat transfer. The conclusion is that jet impingement is effective for cooling applications due to the high heat transfer coefficients that can be achieved.
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.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Diffusers are extensively used in centrifugal
compressors, axial flow compressors, ram jets, combustion
chambers, inlet portions of jet engines and etc. A small change in
pressure recovery can increases the efficiency significantly.
Therefore diffusers are absolutely essential for good turbo
machinery performance. The geometric limitations in aircraft
applications where the diffusers need to be specially designed so
as to achieve maximum pressure recovery and avoiding flow
separation.
The study behind the investigation of flow separation in a planar
diffuser by varying the diffuser taper angle for axisymmetric
expansion. Numerical solution of 2D axisymmetric diffuser model
is validated for skin friction coefficient and pressure coefficient
along upper and bottom wall surfaces with the experimental
results of planar diffuser predicted by Vance Dippold and
Nicholas J. Georgiadis in NASA research center [2]
.
Further the diffuser taper angle is varied for other different
angles and results shows the effect of flow separation were it is
reduces i.e., for what angle and at which angle it is just avoided.
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.
Numerical analysis of heat transfer in refrigerant flow through a condenser tubeeSAT Journals
Abstract In this thesis, heat transfer analysis of refrigerant flow in a condenser tube has been done. The main objective of this thesis is to find the length of the condenser tube for a pre-defined refrigerant inlet state such that the refrigerant at the tube outlet is saturated liquid or sub cooled liquid. The inlet refrigerant condition is saturated vapor. The problem involves refrigerant flowing inside a straight, horizontal copper tube over which air is in cross flow. Inlet condition of the both fluids and condenser tube detail except its length are specified. Here, changing pressure at discrete points along the tube is calculated by using two-phase frictional pressure drop and momentum equation mode. The heat transfer calculation has done by using condensation heat transfer correlations and simple heat transfer equations. The inside heat transfer coefficient calculated by using two phase heat transfer coefficient correlation. The unknown length of condenser tube has discrete many numbers of small elements. Each and every element has a calculations based on the pressure drop as well as heat transfer based on those correlation and every element calculated properties of refrigerant values has to check its states. At end of the iteration, a last element has reached saturated liquid condition of refrigerant and stops the entire calculation. So the length of condenser tube has been calculated by number of iteration and number of nodes with its distance. Predicted values were compared using another condensation heat transfer correlations. A computer-code using Turbo C has been developed for performing the entire calculation. Keywords: Heat transfer, Refrigeration, Multi phase flow, condenser flow, Tube length
Numerical analysis of heat transfer in refrigerant flow through a condenser tubeeSAT Publishing House
The document describes a numerical analysis of heat transfer in refrigerant flow through a condenser tube. The analysis calculates the length of the condenser tube needed such that the refrigerant exits in a saturated liquid or subcooled liquid state, given inlet conditions. It does this by discretizing the tube into nodes and calculating pressure changes and enthalpy changes between nodes using heat transfer and pressure drop correlations. Input parameters like refrigerant properties, mass flow rates, and tube geometry are specified. Results show the required tube length increases as the inner tube diameter decreases due to increased thermal resistance.
Unit I of the document discusses fluid properties and flow characteristics including:
- Defining units and dimensions, properties like density, viscosity, vapor pressure.
- Explaining concepts of control volume and applying continuity, energy, and momentum equations.
- Describing laminar and turbulent flow, boundary layers, and flow through pipes.
The unit provides fundamental concepts and equations for understanding fluid behavior in both static and dynamic conditions.
A Computational Investigation of Flow Structure Within a Sinuous DuctIJERA Editor
In the present investigation the distribution of mean velocity are experimentally studied on three constant area
rectangular curved ducts with an aspect ratio of 2.4. First one is C-shape, second one is S-shape and third one
is a DS-shape duct. The experiment is carried out at mass averaged mean velocity of 40m/s for all the ducts.
The velocity distribution shows for C-duct, the bulk flow shifting from outer wall to the inner wall along the
flow passage and for S-duct, the bulk flow shifting from outer wall to the inner wall in the first half and from
inner wall to the outer wall in the second half along the flow passage of curved ducts are very instinct. Due to
the imbalance of centrifugal force and radial pressure gradient, secondary motions in the forms of counter
rotating vortices have been generated within both the curved duct. For DS-duct the velocity distributions shows
the Bulk of flow shifting from inner watt to outer wall in the first bend and third bend of the duct and outer wall
to inner wall in the second bend and forth bend of the duct along the flow passage is very instinct. Flow at end
of the DS-duct is purely uniform in nature due to non existence of secondary motion. The experimental results
then were numerically validated with the help of Fluent, which shows a good agreement between the
experimental and predicted results for all the ducts
1. Heat exchanger pressure drop analysis is important because pumping power required is directly related to pressure drop and pressure drop affects heat transfer, operation, size, and cost.
2. Major contributions to pressure drop include friction in the core and distribution devices, with core pressure drop dominated by friction, momentum effects, and entrance/exit effects.
3. Core pressure drop is analyzed using assumptions of steady, isothermal flow and accounting for friction, momentum effects, and entrance/exit contractions based on flow geometry and properties.
IRJET-To Investigate the effect of Spinner Geometry on COP of Vortex Tube Ref...IRJET Journal
This document summarizes a research paper that investigates how changing the geometry of the spinner inside a vortex tube affects its coefficient of performance (COP) for refrigeration. The paper describes how a vortex tube works by separating compressed air into hot and cold streams. It then discusses changing the angle of the spinner notches within the vortex tube from 25 to 45 degrees and using computational fluid dynamics (CFD) software to analyze how this affects temperatures and COP. The document reviews previous literature on vortex tube experiments and analysis, and describes the methodology of using CAD software to model different spinner angles and CFD to simulate flow, temperature, and pressure within the vortex tube.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
Numerical Predictions of Enhanced Impingement Jet Cooling with Ribs and Pins ...AZOJETE UNIMAID
This document presents a numerical study of enhanced impingement jet cooling with ribs and pins on target surfaces. Computational fluid dynamics (CFD) simulations were conducted using commercial codes to predict heat transfer with different obstacle wall configurations. The obstacles investigated were ribs and rectangular pin-fins in both co-flow and cross-flow alignments. The CFD predictions showed good agreement with previous experimental results and revealed that obstacles increase turbulence but also reduce the highest thermal gradients and downstream cross-flow.
Aerodynamic Analysis of Low Speed Turbulent Flow Over A Delta WingIJRES Journal
Delta wing has been a subject of intense research since decades due to decades due to inherent characteristics of generating increased nonlinear lift due to vortex dominated flows. Lot of work has been carried out in order to understand the vortex dominated flows on the delta wing. The delta wing is a wing platform in the form of a triangle. Aerodynamics of wings with moderate sweep angle is recognized by the aerospace community as a challenging problem. In spite of its potential application in military aircraft, the understanding of the aerodynamics of such wings is far from complete. In order to address this situation, the present work is initiated to compute the 3D turbulent flow field over sharp edged finite wings with a diamond shaped plan forms and moderate sweep angle. The detailed flow pattern and surface pressure distribution may further indicate the appropriate kind of flow control during flight operation of such wings. The flow field is computed using an in-house developed CFD code RANS3D.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document summarizes a research paper that proposes a machine learning approach for detecting phishing websites. It discusses using heuristic features from CANTINA to train machine learning models. A new domain top-page similarity feature is introduced to improve accuracy. Various modules are described, including site training, site capturing, a phishing dictionary, and image correlation to measure similarity. Experimental results show the approach achieves up to 92.5% f-measure and a 7.5% error rate for phishing detection.
This document describes the design and development of a microcontroller-based system for measuring blood glucose levels. The system uses an amperometric method that relies on glucose oxidase enzymes and a mediator compound to transfer electrons from blood glucose to an electrode, generating an electrical signal. A PIC 18F4520 microcontroller processes, amplifies and converts the signal to a display on an LCD module. The system is intended to be low-cost, portable, and provide frequent blood glucose monitoring to help control diabetes and reduce complications. It works by measuring the current produced from the reaction of blood glucose with glucose oxidase and a mediator compound.
Hydrodynamic study of anadjustableheightpacked column operatingIAEME Publication
This document summarizes a study on the hydrodynamic performance of an adjustable height packed column operating on the principle of an air lift pump. The column is packed with glass rings and operates in a closed water loop with air injection at the base. Water flow rates, pressure drop, gas holdup, and efficiency were measured for different air flow rates and submersion depths. The results show that water flow rate increases with air flow rate and submersion depth. Pressure drop follows a second order polynomial relationship with submersion depth. Gas holdup also increases with air flow rate and decreases with water flow rate. The system provides good mixing with low power consumption and could be used for applications involving heat and mass transfer.
Effect on heat transfer for laminar flow over Backward Facing Step with squar...ijceronline
The purpose of this paper is to study the influence of an adiabatic square cylinder on the heat transfer enhancement in the 2D laminar flow over the Backward Facing Step (BFS). This work also studies the effect of streamwise position of the square cylinder on heat transfer enhancement. The governing equations, for the 2D laminar flow over BFS with a square cylinder placed inside, are solved on nonuniform Cartesian grid using projection method. The individual differential terms of the N-S equations are discretized using a Higher Order Compact Scheme (HOCS). The numerical code is first validated with the results available in the literature. The main advantage of HOCS is to obtain higher order approximations to the derivatives accurately without the necessity of higher number of nodes. Thus reducing the computational cost. It is observed from the numerical experiment that placing the cylinder affects the fluid flow and heat transfer and for XC=1.4, YC = 1.0 and Re= 200, there is a maximum heat transfer enhancement of 193.93%.The results of these numerical experiments are useful in studying the heat transfer enhancement and its dependence on the bluff body and flow characteristics. This work has its applications in engineering problems where the heat transfer in a laminar flow regime can be enhanced using a bluff body. The current work also demonstrates the dependence of horizontal position of cylinder on heat transfer augmentation.
This document summarizes a numerical study of turbulent flow downstream from a linear heat source placed inside the cylinder wake. The study used computational fluid dynamics (CFD) to model the flow and heat transfer at varying Reynolds numbers. The k-ε realizable turbulence model was applied. Results showed that instabilities in the wake zone increase with Reynolds number, forming a von Karman vortex street that influences the thermal field and diffusion process. Comparisons of numerical results to experimental data were satisfactory. The study provides insight into how wake structures impact heat transport and scalar diffusion in turbulent flows.
New Microsoft Office PowerPoint PresentationSudhir Shinde
This document summarizes a seminar presentation on heat transfer via jet impingement. The presentation discusses how jet impingement is used to effectively remove large amounts of heat from surfaces, such as in cooling turbine blades and electronics. It reviews factors that influence heat transfer, including nozzle diameter, jet-to-surface spacing, and Reynolds number. The experimental setup examines heat transfer characteristics of air and water jets impinging on a heated surface. Results show that lower jet diameters and spacings and higher Reynolds numbers increase heat transfer. The conclusion is that jet impingement is effective for cooling applications due to the high heat transfer coefficients that can be achieved.
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.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Diffusers are extensively used in centrifugal
compressors, axial flow compressors, ram jets, combustion
chambers, inlet portions of jet engines and etc. A small change in
pressure recovery can increases the efficiency significantly.
Therefore diffusers are absolutely essential for good turbo
machinery performance. The geometric limitations in aircraft
applications where the diffusers need to be specially designed so
as to achieve maximum pressure recovery and avoiding flow
separation.
The study behind the investigation of flow separation in a planar
diffuser by varying the diffuser taper angle for axisymmetric
expansion. Numerical solution of 2D axisymmetric diffuser model
is validated for skin friction coefficient and pressure coefficient
along upper and bottom wall surfaces with the experimental
results of planar diffuser predicted by Vance Dippold and
Nicholas J. Georgiadis in NASA research center [2]
.
Further the diffuser taper angle is varied for other different
angles and results shows the effect of flow separation were it is
reduces i.e., for what angle and at which angle it is just avoided.
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.
Numerical analysis of heat transfer in refrigerant flow through a condenser tubeeSAT Journals
Abstract In this thesis, heat transfer analysis of refrigerant flow in a condenser tube has been done. The main objective of this thesis is to find the length of the condenser tube for a pre-defined refrigerant inlet state such that the refrigerant at the tube outlet is saturated liquid or sub cooled liquid. The inlet refrigerant condition is saturated vapor. The problem involves refrigerant flowing inside a straight, horizontal copper tube over which air is in cross flow. Inlet condition of the both fluids and condenser tube detail except its length are specified. Here, changing pressure at discrete points along the tube is calculated by using two-phase frictional pressure drop and momentum equation mode. The heat transfer calculation has done by using condensation heat transfer correlations and simple heat transfer equations. The inside heat transfer coefficient calculated by using two phase heat transfer coefficient correlation. The unknown length of condenser tube has discrete many numbers of small elements. Each and every element has a calculations based on the pressure drop as well as heat transfer based on those correlation and every element calculated properties of refrigerant values has to check its states. At end of the iteration, a last element has reached saturated liquid condition of refrigerant and stops the entire calculation. So the length of condenser tube has been calculated by number of iteration and number of nodes with its distance. Predicted values were compared using another condensation heat transfer correlations. A computer-code using Turbo C has been developed for performing the entire calculation. Keywords: Heat transfer, Refrigeration, Multi phase flow, condenser flow, Tube length
Numerical analysis of heat transfer in refrigerant flow through a condenser tubeeSAT Publishing House
The document describes a numerical analysis of heat transfer in refrigerant flow through a condenser tube. The analysis calculates the length of the condenser tube needed such that the refrigerant exits in a saturated liquid or subcooled liquid state, given inlet conditions. It does this by discretizing the tube into nodes and calculating pressure changes and enthalpy changes between nodes using heat transfer and pressure drop correlations. Input parameters like refrigerant properties, mass flow rates, and tube geometry are specified. Results show the required tube length increases as the inner tube diameter decreases due to increased thermal resistance.
Unit I of the document discusses fluid properties and flow characteristics including:
- Defining units and dimensions, properties like density, viscosity, vapor pressure.
- Explaining concepts of control volume and applying continuity, energy, and momentum equations.
- Describing laminar and turbulent flow, boundary layers, and flow through pipes.
The unit provides fundamental concepts and equations for understanding fluid behavior in both static and dynamic conditions.
A Computational Investigation of Flow Structure Within a Sinuous DuctIJERA Editor
In the present investigation the distribution of mean velocity are experimentally studied on three constant area
rectangular curved ducts with an aspect ratio of 2.4. First one is C-shape, second one is S-shape and third one
is a DS-shape duct. The experiment is carried out at mass averaged mean velocity of 40m/s for all the ducts.
The velocity distribution shows for C-duct, the bulk flow shifting from outer wall to the inner wall along the
flow passage and for S-duct, the bulk flow shifting from outer wall to the inner wall in the first half and from
inner wall to the outer wall in the second half along the flow passage of curved ducts are very instinct. Due to
the imbalance of centrifugal force and radial pressure gradient, secondary motions in the forms of counter
rotating vortices have been generated within both the curved duct. For DS-duct the velocity distributions shows
the Bulk of flow shifting from inner watt to outer wall in the first bend and third bend of the duct and outer wall
to inner wall in the second bend and forth bend of the duct along the flow passage is very instinct. Flow at end
of the DS-duct is purely uniform in nature due to non existence of secondary motion. The experimental results
then were numerically validated with the help of Fluent, which shows a good agreement between the
experimental and predicted results for all the ducts
1. Heat exchanger pressure drop analysis is important because pumping power required is directly related to pressure drop and pressure drop affects heat transfer, operation, size, and cost.
2. Major contributions to pressure drop include friction in the core and distribution devices, with core pressure drop dominated by friction, momentum effects, and entrance/exit effects.
3. Core pressure drop is analyzed using assumptions of steady, isothermal flow and accounting for friction, momentum effects, and entrance/exit contractions based on flow geometry and properties.
IRJET-To Investigate the effect of Spinner Geometry on COP of Vortex Tube Ref...IRJET Journal
This document summarizes a research paper that investigates how changing the geometry of the spinner inside a vortex tube affects its coefficient of performance (COP) for refrigeration. The paper describes how a vortex tube works by separating compressed air into hot and cold streams. It then discusses changing the angle of the spinner notches within the vortex tube from 25 to 45 degrees and using computational fluid dynamics (CFD) software to analyze how this affects temperatures and COP. The document reviews previous literature on vortex tube experiments and analysis, and describes the methodology of using CAD software to model different spinner angles and CFD to simulate flow, temperature, and pressure within the vortex tube.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
Numerical Predictions of Enhanced Impingement Jet Cooling with Ribs and Pins ...AZOJETE UNIMAID
This document presents a numerical study of enhanced impingement jet cooling with ribs and pins on target surfaces. Computational fluid dynamics (CFD) simulations were conducted using commercial codes to predict heat transfer with different obstacle wall configurations. The obstacles investigated were ribs and rectangular pin-fins in both co-flow and cross-flow alignments. The CFD predictions showed good agreement with previous experimental results and revealed that obstacles increase turbulence but also reduce the highest thermal gradients and downstream cross-flow.
Aerodynamic Analysis of Low Speed Turbulent Flow Over A Delta WingIJRES Journal
Delta wing has been a subject of intense research since decades due to decades due to inherent characteristics of generating increased nonlinear lift due to vortex dominated flows. Lot of work has been carried out in order to understand the vortex dominated flows on the delta wing. The delta wing is a wing platform in the form of a triangle. Aerodynamics of wings with moderate sweep angle is recognized by the aerospace community as a challenging problem. In spite of its potential application in military aircraft, the understanding of the aerodynamics of such wings is far from complete. In order to address this situation, the present work is initiated to compute the 3D turbulent flow field over sharp edged finite wings with a diamond shaped plan forms and moderate sweep angle. The detailed flow pattern and surface pressure distribution may further indicate the appropriate kind of flow control during flight operation of such wings. The flow field is computed using an in-house developed CFD code RANS3D.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document summarizes a research paper that proposes a machine learning approach for detecting phishing websites. It discusses using heuristic features from CANTINA to train machine learning models. A new domain top-page similarity feature is introduced to improve accuracy. Various modules are described, including site training, site capturing, a phishing dictionary, and image correlation to measure similarity. Experimental results show the approach achieves up to 92.5% f-measure and a 7.5% error rate for phishing detection.
This document describes the design and development of a microcontroller-based system for measuring blood glucose levels. The system uses an amperometric method that relies on glucose oxidase enzymes and a mediator compound to transfer electrons from blood glucose to an electrode, generating an electrical signal. A PIC 18F4520 microcontroller processes, amplifies and converts the signal to a display on an LCD module. The system is intended to be low-cost, portable, and provide frequent blood glucose monitoring to help control diabetes and reduce complications. It works by measuring the current produced from the reaction of blood glucose with glucose oxidase and a mediator compound.
This document summarizes a research paper that proposes using a genetic algorithm to generate high-quality association rules for measuring data quality. The genetic algorithm evaluates rules based on four metrics: confidence, completeness, comprehensibility, and interestingness. It aims to discover high-level prediction rules that perform better than traditional greedy rule induction algorithms at handling attribute interactions. The genetic algorithm represents rules as chromosomes and uses the four metrics as an objective fitness function to evaluate the quality of each rule.
The document describes a genetic algorithm approach to optimizing the design of steel-concrete composite plane frames to minimize cost. The algorithm uses design variables like beam and column cross-sectional properties to represent potential solutions. It evaluates solutions based on structural analysis and design constraints like moments, shear, buckling and axial forces. The best solution from each generation is preserved to guide the evolution toward an optimal, cost-effective frame design. The approach is demonstrated on example frames.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document discusses software security metrics and validating UML diagrams using metrics. It provides background on using metrics to measure quality attributes of object-oriented designs. Traditional code-level security metrics are insufficient and evaluating security at the design level is important. The paper proposes a system that applies design-level security metrics using genetic algorithms to generate secure design options from a UML diagram. It then implements code from the designs and applies the same metrics at the code level to validate that the code matches the intended secure design. This allows discovering and fixing security issues earlier in the development process.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The document proposes two new authentication schemes for PDAs that use session passwords. Session passwords are one-time passwords generated for each login. The first scheme generates passwords based on pairs of letters from a secret text password and their intersections on a grid. The second scheme has users rate colors during registration, and session passwords are generated by the intersections of those colors on a color grid and number grid displayed during login. Both schemes aim to be resistant to dictionary attacks, brute force attacks, and shoulder surfing by changing the grids each time. The techniques were proposed to provide authentication for PDAs but require further testing for usability and effectiveness.
This document summarizes and compares four routing algorithms for mobile ad hoc networks: Disjoint Multipath Routing, Trust based Multipath Routing, Message Trust based Multipath Routing, and a new proposed algorithm called Friend Based Ad-hoc Routing. It describes the key mechanisms of each algorithm, including how they establish routes, incorporate trust levels, and handle packet routing. The proposed FACES algorithm aims to improve security and efficiency by using friend, unauthenticated, and question mark lists to identify trusted routes and avoid malicious nodes.
This document discusses the performance analysis and minimization of black hole attacks in mobile ad hoc networks (MANETs). It begins with an introduction to MANETs and discusses how they are vulnerable to black hole attacks. The document then describes the AODV routing protocol and how black hole attacks exploit vulnerabilities in the route discovery process. Existing detection and prevention techniques are outlined. The document proposes modifying the AODV protocol to implement an intrusion detection system (IDSAODV) that can detect and discard fraudulent route replies from black hole nodes, improving packet delivery. Simulation scenarios of varying node counts with and without black holes are used to analyze black hole behavior and evaluate the effectiveness of the IDSAODV approach.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The document discusses the characterization and numerical optimization of chromium-free nickel alloy filler materials for dissimilar welding between stainless steel SS304. Eight alloys with compositions ranging from 40-43.5% Ni, 4-20% Mo, 0-16% Co, 10% Cu, 22-25% Fe, 0.5% Al, 1% Ti, and 0.001% C were analyzed. JMatPro software was used to simulate phases present at different temperatures. Welding simulations using ANSYS evaluated residual stresses in the welds. The alloy with 43.499% Ni, 0.5% Al, 14% Co, 6% Mo, 10% Cu, 23% Fe, 2% Mn, 1
This document presents a study on using color texture feature analysis to detect surface defects on pomegranates. The researchers developed a method involving cropping images of pomegranates, converting them to HSI color space, generating SGDM matrices to extract 18 texture features for each image, and using support vector machines (SVM) classification to identify the best features for detecting infections. The optimal features identified were cluster shade, product moment, and mean intensity, achieving classification accuracy of 99.88%, 99.88%, and 99.81% respectively.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document summarizes a study investigating fluid flow through two-dimensional sudden expansions and contractions. The study uses computational fluid dynamics (CFD) to simulate fluid flow through axisymmetric geometries with varying diameter ratios and Reynolds numbers. Results are presented on flow characteristics like recirculation zones, reattachment lengths, and vortex strengths. Validation is provided by comparing simulations to experimental particle image velocimetry data. Key findings include higher instability at lower Reynolds numbers for large expansion ratios and variations in recirculation zone size and redeveloped flow with changes in Reynolds number and diameter ratio.
1. The Industrial Flow Modeling Group at the National Chemical Laboratory in Pune, India conducts research on multiphase fluid dynamics and develops tools for chemical reactor engineering.
2. The group has published over 40 papers, secured over Rs. 1.2 crore in external funding, and has established experimental and computational facilities for their work.
3. Current activities include research on dispersed gas-liquid flows, bubble columns, trickle bed reactors, and collaborations with universities in France and the US.
A comparatively analysis of plate type H.E. and helical type H.E. using ANOVA...IRJET Journal
This document compares plate type and helical type heat exchangers using ANOVA analysis. It first describes the design and operation of each type of heat exchanger. It then outlines the methodology used, including equations for heat transfer coefficients and an overview of ANOVA analysis. The results section describes the design of each heat exchanger in CATIA software and presents graphs comparing their pressure drops and R2 regression factors. Finally, it concludes the plate heat exchanger offers advantages in terms of space, heat transfer efficiency, turbulence, flexibility and lifespan.
THE EFFECT OF GEOMETRICAL PARAMETERS ON HEAT TRANSFER AND HYDRO DYNAMICAL CHA...ijmech
Compact size and high heat transfer coefficient of helical coil heat exchangers causes them to have an
important role in various industrial applications. This paper investigate numerically on the influence of
different parameters such as coil radius, coil pitch and diameter of tube on the hydrodynamic and
heat transfer characteristics of helical double tube heat exchangers using the CFD software which is
based on the principles of heat transfer, fluid mechanics and thermodynamics. The results indicated that
heat transfer augmentation occurs by increasing of the inner Dean Number, inner tube diameter, curvature
ratio and by the reduction of the pitch of heat exchanger coil. By increasing the radius of coils, the
secondary flow effects due to centrifugal forces diminishes and flow of fluid through the coils tends to flow
in a straight path and as a result, the friction coefficient decreases consequently.
Heat Transfer & Periodic Flow Analysis of Heat Exchanger by CFD with Nano FluidsIJERA Editor
Many heat transfer applications such as steam generators in a boiler or air cooling coil of an air conditioner, can
be modelled in a bank of tubes containing a fluid flowing at one temperature that is immersed in a second fluid
in a cross flow at different temperature. CFD simulations are a useful tool for understanding flow and heat
transfer principles as well as for modelling these types of geometries. Both the fluids considered in the present
study are CUO Nano fluids, and flow is classified as laminar and steady with Reynolds number between 100-
600.The mass flow rate of the cross flow and diameter has been varied (such as 0.05, 0.1, 0.15, 0.20, 0.25, 0.30
kg/sec and 0.8, 1.0.1.2 &1.4cm) and the models are used to predict the flow and temperature fields that result
from convective heat transfer. Due to symmetry of the tube bank and the periodicity of the flow inherent in the
tube bank geometry, only a portion of the geometry will be modelled and with symmetry applied to the outer
boundaries. The inflow boundary will be redefined as a periodic zone and the outflow boundary is defined as the
shadow. The various static pressures, velocities, and temperatures obtained are reported.
In this present project tubes of different diameters and different mass flow rates are considered to examine the
optimal flow distribution. Further the problem has been subjected to effect of materials used for tubes
manufacturing on heat transfer rate. Materials considered are copper and Nickle Chromium alloys. Results
emphasize the utilization of alloys in place of copper as tube material serves better heat transfer with most
economical way.
Heat Transfer & Periodic Flow Analysis of Heat Exchanger by CFD with Nano FluidsIJERA Editor
Many heat transfer applications such as steam generators in a boiler or air cooling coil of an air conditioner, can
be modelled in a bank of tubes containing a fluid flowing at one temperature that is immersed in a second fluid
in a cross flow at different temperature. CFD simulations are a useful tool for understanding flow and heat
transfer principles as well as for modelling these types of geometries. Both the fluids considered in the present
study are CUO Nano fluids, and flow is classified as laminar and steady with Reynolds number between 100-
600.The mass flow rate of the cross flow and diameter has been varied (such as 0.05, 0.1, 0.15, 0.20, 0.25, 0.30
kg/sec and 0.8, 1.0.1.2 &1.4cm) and the models are used to predict the flow and temperature fields that result
from convective heat transfer. Due to symmetry of the tube bank and the periodicity of the flow inherent in the
tube bank geometry, only a portion of the geometry will be modelled and with symmetry applied to the outer
boundaries. The inflow boundary will be redefined as a periodic zone and the outflow boundary is defined as the
shadow. The various static pressures, velocities, and temperatures obtained are reported.
In this present project tubes of different diameters and different mass flow rates are considered to examine the
optimal flow distribution. Further the problem has been subjected to effect of materials used for tubes
manufacturing on heat transfer rate. Materials considered are copper and Nickle Chromium alloys. Results
emphasize the utilization of alloys in place of copper as tube material serves better heat transfer with most
economical way
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.
A REPORT ON HEAT TRANSFER OPTIMIZATION OFSHELL AND TUBE HEAT EXCHANGER USING ...IRJET Journal
The document presents a study on optimizing heat transfer in a shell and tube heat exchanger using different fluids through computational fluid dynamics (CFD) analysis. A shell and tube heat exchanger model was created in CATIA software and CFD analysis was performed in Solidworks Flow Simulation. Water and two types of nanofluids (SiO2 and Al2O3 nanoparticles mixed with water) were analyzed as fluids flowing through the heat exchanger tubes at varying velocities from 0.2 m/s to 1 m/s. The results found that increasing fluid velocity improved heat transfer effectiveness and overall heat transfer while decreasing friction factor. Heat transfer performance was highest for the nanofluids compared to water alone.
This document reviews computational fluid dynamics (CFD) analysis and experimental work on the laser ablation process for producing carbon nanotubes. It discusses how CFD can be used to simulate the plume dynamics and temperature/pressure profiles during laser ablation. While some studies have performed 2D analysis of the furnace geometry, the document suggests there is still scope for 3D CFD analysis to better understand the phenomena. It surveys several past experimental and computational investigations on laser ablation for nanotube production.
IRJET- Numerical Investigation of Heat Transfer Enhancement in Circular Pipe ...IRJET Journal
1. The document numerically investigates heat transfer enhancement in a circular pipe with various rib geometries, including flat, conical, and right angle ribs.
2. It uses computational fluid dynamics to model water flow through the pipe with Reynolds numbers from 5000 to 60000 and a constant heat flux of 50 W/cm2 applied to the pipe surface.
3. The results show that ribs on the inside of the pipe enhance turbulence in the flow and produce recirculation, disturbing the thermal boundary layer and increasing the rate of heat transfer through the pipe.
This document presents a numerical analysis of heat transfer enhancement in pipe-in-pipe helical coiled heat exchangers. A computational fluid dynamics (CFD) analysis was conducted to determine the effect of varying parameters like inner tube diameter, mass flow rates, and flow configuration (parallel vs. counter flow) on heat transfer characteristics. The CFD results showed that decreasing the inner tube diameter and increasing the mass flow rates led to higher overall heat transfer coefficients. Counter flow configuration provided better heat transfer than parallel flow. Validation of the CFD model showed decent agreement with existing empirical correlations for heat transfer in helical coils.
Numerical Analysis of Heat Transfer Enhancement in Pipe-inPipe Helical Coiled...iosrjce
This document presents a numerical analysis of heat transfer enhancement in pipe-in-pipe helical coiled heat exchangers. Computational fluid dynamics (CFD) was used to analyze the effect of varying parameters like inner tube diameter, mass flow rates, and flow configuration (parallel vs. counter flow). The results show that overall heat transfer coefficients increase with increasing inner Dean number and mass flow rates. Heat transfer rates also increase with higher inner mass flow rates. Counter flow configuration provides better heat transfer than parallel flow. Increasing the inner tube size decreases the total heat transfer rate due to a reduction in annulus cross-sectional area. Measured inner Nusselt numbers agree reasonably well with existing correlations.
This document presents a numerical analysis of heat transfer enhancement in pipe-in-pipe helical coiled heat exchangers. Computational fluid dynamics (CFD) was used to analyze the effect of varying parameters like inner tube diameter, mass flow rates, and coil configuration on heat transfer characteristics. The results show that overall heat transfer coefficient increases with increasing inner Dean number and decreasing inner tube diameter. Counter-flow configuration provides better heat transfer than parallel flow. Validation of CFD results was done using existing Nusselt number correlations from literature. Increasing tube size or annulus mass flow rate decreases the total heat transfer rate.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
This document provides an introduction to computational fluid dynamics (CFD) simulations of heat transfer in a tube bank heat exchanger. It discusses how CFD can be used to model the complex flow patterns and heat transfer between two fluids in a tube bank. The objectives are to examine optimal flow distribution for tubes of varying diameters and mass flow rates, and to analyze the effect of different tube materials on heat transfer rates. CFD provides insights into heat transfer phenomena at a lower cost than physical experiments.
Numerical Analysis of the Effects of Baffle orientation and shape factor on P...IRJET Journal
This document numerically analyzes the effects of baffle orientation and shape factor on pressure drop and heat transfer coefficient in a tube heat exchanger. It discusses using baffles inside heat exchanger channels to create recirculation zones that disturb the fluid flow and enhance convective heat transfer. The study examines baffles installed at various angles and with different shapes in a rectangular channel using simulations. Results show that a baffle sloped at 30 degrees increases the Nusselt number by nearly 26% compared to a flat baffle. Orienting baffles in the flow direction and increasing the blocking factor also enhances heat transfer.
Comparative Analysis Fully Developed Turbulent Flow in Various Arbitrary Cros...IRJET Journal
This document presents a comparative computational fluid dynamics (CFD) analysis of fully developed turbulent flow in circular, triangular, and rectangular cross-section pipes using the finite volume method. The study examines the flow of water at high Reynolds numbers using the k-ε turbulence model. Contour plots show that triangular duct has the highest dynamic pressure at the outlet, while rectangular duct has higher dynamic pressure than circular duct at the center and outlet. Turbulent intensity graphs indicate intensity increases more significantly after certain distances in circular and triangular ducts, but continuously increases along the rectangular duct length due to less variation in boundary layer and viscous sublayer.
CFD Analysis of Plate Fin Tube Heat Exchanger for Various Fin InclinationsIJERA Editor
ANSYS Fluent software is used for three dimensional CFD simulations to investigate heat transfer and fluid flow characteristics of six different fin angles with plain fin tube heat exchangers. The numerical simulation of the fin tube heat exchanger was performed by using a three dimensional numerical computation technique. Geometry of model is created and meshed by using ANSYS Workbench software. To solve the equation for the fluid flow and heat transfer analysis ANSYS FLUENT was used in the fin-tube heat exchanger. The fluid flow and heat transfer are simulated and result compared for both laminar and turbulent flow models k-epsilon and SST k-omega, with steady state solvers to calculate heat transfer, flow velocity and temperature fields of variable inclined fin angles (Ɵ = 00,100 , 200, 300, 400,500). Model is validate by comparing the simulated value of velocity, temperature and colburn factor with experimental and numerical results investigated by WANG [1] and GHORI KIRAR [10]. Reasonable agreement is found between the simulations and other results, and the ANSYS Fluent software is sufficient for simulating the flow fields in tube fin heat exchanger.
This document summarizes research on heat transfer augmentation techniques in circular and non-circular tubes. Both active and passive methods are used, with passive methods not requiring external power. For circular tubes, research is reviewed on using displaced inserts like twisted tapes and wire coil inserts in laminar and turbulent flow. Heat transfer enhancement of up to 36% was achieved in laminar flow and up to 9.8 times in turbulent flow compared to plain tubes. Computational fluid dynamics (CFD) analysis was also used to study flow and heat transfer with inserts. For non-circular tubes, heat transfer in ducts with triangular, rectangular, and trapezoidal cross-sections was investigated.
NUMERICAL ANALYSIS TO OPTIMIZE THE HEAT TRANSFER RATE OF TUBE-IN-TUBE HELICAL...Netha Jashuva
The document discusses numerical analysis to optimize the heat transfer rate of tube-in-tube helical coil heat exchangers. It begins with an introduction to heat exchangers and computational fluid dynamics (CFD) modeling. It then reviews previous literature on optimizing heat transfer rates in helical coil heat exchangers through varying parameters like coil diameter, pitch, fluid flow rates, and using nanofluids. The literature survey found that increasing the Dean number through these parameters generally increases heat transfer rates, though it also increases pumping power requirements. The goal of the project is to find the optimal point where increased heat transfer rates outweigh increased power needs.
IRJET- Numerical Investigation of the Forced Convection using Nano FluidIRJET Journal
This document summarizes research on using computational fluid dynamics (CFD) simulations to analyze heat transfer and friction factors for turbulent flow of titanium dioxide, iron oxide, and silicon dioxide nanofluid in semi-circle corrugated channels. The simulations were conducted at Reynolds numbers of 10,000-30,000, nanoparticle volume fractions of 0-6%, and constant heat flux conditions. Results showed that the Nusselt number, a measure of heat transfer, increased with higher nanoparticle volume fraction and Reynolds number. Maximum Nusselt number enhancement of 2.07 was found at a Reynolds number of 30,000 and volume fraction of 6%.
IRJET- Design the Shell and Tube Heat Exchanger with the Help of Programming ...IRJET Journal
This document discusses the design of a shell and tube heat exchanger using MATLAB software. It begins with an abstract that outlines how heat exchangers transfer heat between fluids and research into increasing heat exchanger effectiveness. It then provides background on heat exchangers and discusses prior research on improving shell and tube heat exchanger design, notably methods developed by Kern, Tinker, Bell, Saunders, Taborek, Wills and Johnston, and others. The document indicates that while hand calculations were used historically, computer programs are now widely employed for heat exchanger design.
Skybuffer SAM4U tool for SAP license adoptionTatiana Kojar
Manage and optimize your license adoption and consumption with SAM4U, an SAP free customer software asset management tool.
SAM4U, an SAP complimentary software asset management tool for customers, delivers a detailed and well-structured overview of license inventory and usage with a user-friendly interface. We offer a hosted, cost-effective, and performance-optimized SAM4U setup in the Skybuffer Cloud environment. You retain ownership of the system and data, while we manage the ABAP 7.58 infrastructure, ensuring fixed Total Cost of Ownership (TCO) and exceptional services through the SAP Fiori interface.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
BIO: Sostenitrice del software libero e dei formati standard e aperti. È stata un membro attivo dei progetti Fedora e openSUSE e ha co-fondato l'Associazione LibreItalia dove è stata coinvolta in diversi eventi, migrazioni e formazione relativi a LibreOffice. In precedenza ha lavorato a migrazioni e corsi di formazione su LibreOffice per diverse amministrazioni pubbliche e privati. Da gennaio 2020 lavora in SUSE come Software Release Engineer per Uyuni e SUSE Manager e quando non segue la sua passione per i computer e per Geeko coltiva la sua curiosità per l'astronomia (da cui deriva il suo nickname deneb_alpha).
Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
Best 20 SEO Techniques To Improve Website Visibility In SERPPixlogix Infotech
Boost your website's visibility with proven SEO techniques! Our latest blog dives into essential strategies to enhance your online presence, increase traffic, and rank higher on search engines. From keyword optimization to quality content creation, learn how to make your site stand out in the crowded digital landscape. Discover actionable tips and expert insights to elevate your SEO game.
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
- Discover ArgoCD, a declarative, GitOps continuous delivery tool for Kubernetes, and its role in deploying applications on edge devices.
4. Deployment Using ArgoCD for Edge Devices
- Step-by-step guide on deploying anomaly detection models on edge devices using ArgoCD.
5. Introduction to Apache Kafka and S3
- Explore Apache Kafka for real-time data streaming and Amazon S3 for scalable storage solutions.
6. Viewing Kafka Messages in the Data Lake
- Learn how to view and analyze Kafka messages stored in a data lake for better insights.
7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
- Detailed instructions on setting up Prometheus to monitor the performance and health of your anomaly detection system.
9. What is Camel K?
- Introduction to Camel K, a lightweight integration framework built on Apache Camel, designed for Kubernetes.
10. Configuring Camel K Integrations for Data Pipelines
- Learn how to configure Camel K for seamless data pipeline integrations in your anomaly detection workflow.
11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
- Hands-on examples and code snippets in Jupyter Notebooks to help you implement and test anomaly detection models.
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
A Mix Chart displays historical data of numbers in a graphical or tabular form. The Kalyan Rajdhani Mix Chart specifically shows the results of a sequence of numbers over different periods.
Programming Foundation Models with DSPy - Meetup SlidesZilliz
Prompting language models is hard, while programming language models is easy. In this talk, I will discuss the state-of-the-art framework DSPy for programming foundation models with its powerful optimizers and runtime constraint system.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/building-and-scaling-ai-applications-with-the-nx-ai-manager-a-presentation-from-network-optix/
Robin van Emden, Senior Director of Data Science at Network Optix, presents the “Building and Scaling AI Applications with the Nx AI Manager,” tutorial at the May 2024 Embedded Vision Summit.
In this presentation, van Emden covers the basics of scaling edge AI solutions using the Nx tool kit. He emphasizes the process of developing AI models and deploying them globally. He also showcases the conversion of AI models and the creation of effective edge AI pipelines, with a focus on pre-processing, model conversion, selecting the appropriate inference engine for the target hardware and post-processing.
van Emden shows how Nx can simplify the developer’s life and facilitate a rapid transition from concept to production-ready applications.He provides valuable insights into developing scalable and efficient edge AI solutions, with a strong focus on practical implementation.
Ocean lotus Threat actors project by John Sitima 2024 (1).pptxSitimaJohn
Ocean Lotus cyber threat actors represent a sophisticated, persistent, and politically motivated group that poses a significant risk to organizations and individuals in the Southeast Asian region. Their continuous evolution and adaptability underscore the need for robust cybersecurity measures and international cooperation to identify and mitigate the threats posed by such advanced persistent threat groups.
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
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Presentation of the OECD Artificial Intelligence Review of Germany
Hr2413591363
1. Rahul B Patel, Dr. V. N. Bartaria , Tausif M Shaikh / International Journal of Engineering
Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.1359-1363
A Review On Exprimental & Numerical Investigation Of
Ranque Hilsch Vortextube
Rahul B Patela , Dr. V. N. Bartariab , Tausif M Shaikhc
Abstract-
The vortex tube or Ranque–Hilsch inlet pressure and speed. Pressure difference occurs
vortex tube is a simple device used in industry between tube wall and tube center because of the
for generation of cold and hot air streams from friction of the fluid circling at high speeds. Speed
a single compressed air supply. This simple of the fluid near the tube wall is lower than the
device is very efficient in separation of air speed at the tube center, because of the effects of
streams of different temperatures and has been wall friction. As a result, fluid in the center region
the focus of investigation since the tube’s transfers energy to the fluid at the tube wall,
discovery. Different explanations for the depending on the geometric structure of the vortex
phenomenon of the energy separation have been tube. The cooled fluid leaves the vortex tube from
proposed, however there has not been a the cold output side, by moving towards an
consensus in the hypothesis. The purpose of this opposite direction, compared to the main flow
paper is to present a critical review of current direction, after a stagnation point. Whereas, the
explanations on the working concept of a vortex heated fluid leaves the tube in the main flow
tube. direction from the other end (Dincer et al., in
Although many experimental and numerical press). By injecting compressed air at room
studies on the vortex tubes have been made, the temperature circumferentially into a tube at high
physical behaviour of the flow is not fully velocity, a vortex tube can produce cold air down to
understood due to its complexity and the lack of 223 K and hot air up to 400 K (Crocker et al.,
consistency in the experimental findings. 2003).
Furthermore, several different hypotheses based
on experimental, analytical, and numerical
studies have been put forward to describe the
thermal separation phenomenon. Hypotheses of
pressure, viscosity, turbulence & temperature
separation phenomenon using CFD analysis of
vortex tube are discussed in the paper, and
presumably, future research will benefit from
this discussion.[1]
.
Index Terms—RHVT, Thermal Separation, CFD
I. INTRODUCTION
Ranque discovered the effect of vortex
energy distribution and patented the first vortex
tube (RHVT) in 1934. In 1946, Hilsch improved
the RHVT design and its underlying principles that
still remain valid today (Khodorkov et al., 2003).
Aljuwayhel et al. (2005) define the vortex tube as a
simple device with no moving parts that is capable
of separating a high-pressure flow into two lower
pressure flows of different temperatures. The
device consists of a simple circular tube, one or
more tangential nozzles, and a throttle valve (see
Fig. 1, Cockerill, 1995).
Working principle of the counter flow RHVT can
be defined as follows. Compressible fluid, which is Fig. 1 – Schematic diagram of the counter flow
tangentially introduced into the vortex tube from RHVT (Cockerill, 1995).
nozzles, starts to make a circular movement inside
the vortex tube at high speeds, because of the Schematic diagram of the parallel flow
cylindrical structure of the tube, depending on its RHVT is shown in Fig. 2. Both hot and cold flows
1359 | P a g e
2. Rahul B Patela, Dr. V. N. Bartariab ,Tausif M Shaikhc / International Journal of Engineering
Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.
in RHVTs leave the vortex tube in the same on which physics can be applied for getting the
direction. It is not possible for cold flow to turn results. The CFD software gives one the power to
back after a stagnation point. In order to separate model things, mesh them, give proper boundary
the flow in the center of the tube from the flow at conditions and simulate them with real world
the wall, an apparatus which has a hole in the condition to obtain results. Using CFD a model can
center is used. The temperature of hot and cold be developed which can breed to give results such
flows can be changed by back and forth movement that the model could be developed into an object
of this apparatus. In parallel flow RHVTs, hot and which could be of some use in our life.
cold flows mix with each other. This mixing affects
the temperatures of fluids negatively and causes Modeling is the mathematical physics problem
their efficiencies to be low. For this reason, parallel formulation in terms of a continuous initial
flow RHVTs are generally not preferred (Dincer, boundary value problem (IBVP)
2005; Dincer et al., 2005) IBVP is in the form of Partial Differential
Equations (PDEs) with appropriate boundary
conditions and initial conditions.
Modeling includes:
1. Geometry and domain
2. Coordinates
3. Governing equations
4. Flow conditions
5. Initial and boundary conditions
6. Selection of models for different applications
Solve the Navier-Stokes equations (3D in Cartesian
coordinates) .
Fig. 2 – Schematic diagram of the parallel flow
RHVT (Dincer et al., 2005). Computational fluid dynamics techniques
have revolutionized engineering design in several
In the conventional vortex tube, important areas, notably in analysis of fluid flow
compressed gas enters directly a circular flow technology. CFD can also be used as a minimal
passage with equal section area from a straight adequate tool for design of engineering
pipe, which can cause a sudden change of flow components. A careful scanning of various
direction at the joint between the straight pipe and numerical investigations on the mechanism of
the circular flow passage. The sudden change thermal separation in vortex tubes indicate that
would lead to the generation of eddies, which cause barring a few ,no serious attempts have been made
energy loss. The sudden change of flow velocity to use CFD techniques to simulate the flow patterns
and the eddy generated by this change can also of vortex tubes.
cause the energy loss. It is important to have a high
peripheral velocity in the portion of the tube A detailed analysis of various parameters
immediately after the nozzle; the curve of the of the vortex tube has been carried out through
nozzle affects the performance of vortex tubes (Wu CFD techniques to simulate the phenomenon of
et al., 2007). flow pattern, thermal separation, pressure gradient
RHVTs are used, among others, for cooling, etc. so that they are comparable with the
heating, drying and snow production. Their cooling experimental results.
capability is used, e.g., in dehumidifying gas
samples, chilling of environmental chambers, The vortex tube was first observed by
cooling of food, welding, and air climate control Ranque. Later, Hilsch did some experimental and
processes. Although, they are not very efficient as a theoretical studies to increase the efficiency of the
cooling device, they can be very useful in certain vortex tube. Fulton explained the energy separation.
applications as they are small, simple to make and He proposed that the inner layer heat the outer layer
repair, and require no electrical or chemical power meanwhile expanding and growing cold. Reynolds
source. Nowadays, RHVTs are produced by did the numerical analysis of vortex tube. Lewellen
different commercial companies with a wide range arrived at the solution by combining the three
of applications (Dincer et al., 2008). [2] Navier-stokes equations for an incompressible fluid
in a strong rotating axisymmetric flow with a radial
II. INTRODUCTION TO CFD sink flow. Linderstorm-lang examined the velocity
MODELLING and thermal fields in the tube. He calculated the
CFD is concerned with numerical solution axial and radial gradients of the tangential velocity
of differential equations governing transport of profile from prescribed secondary flow functions
mass, momentum and energy in moving fluid. on the basis of a zero-order approximation to the
Using CFD, one can build a computational model
1360 | P a g e
3. Rahul B Patel, Dr. V. N. Bartaria , Tausif M Shaikh / International Journal of Engineering
Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.1359-1363
momentum equations developed by Lewellen for an parameters for obtaining the maximum hot gas
incompressible flow. temperature and minimum cold gas temperature are
obtained through CFD analysis and validated
Schlenz investigated numerically in a uni- through experiments. The coefficient of
flow vortex tube, the flow field and the process of performance (COP) of the vortex tube as a heat
energy separation. Calculations were carried out engine and as a refrigerator has been calculated.
assuming a 2D axisymmetric compressible flow
and using the Galerkin's approach with a zero- Ahmet Murat Pinar et al, [6] were carried
equation turbulence model to solve the mass, out Optimization of counter flow Ranque–Hilsch
momentum, and energy conservation equations to vortex tube performance using Taguchi method.
calculate the flow and thermal fields. Amitani used This study discusses the application of Taguchi
the mass, momentum and energy conservation method in assessing maximum temperature
equation in a 2D model of a counter flow vortex gradient for the Ranque–Hilsch counter flow vortex
tube with a short length, with an assumption of a tube performance. The experiments were planned
helical motion in an axial direction for an invicid based on Taguchi’s L27 orthogonal array with each
compressible perfect fluid. Flohlingsdorf and Unger trial performed under different conditions of inlet
used the CFX system with the k-ϵ model to study pressure, nozzle number and fluid type. Signal-to-
the velocity profile and energy separation in a noise ratio (S/N) analysis, analysis of variance
vortex tube. Aljuwahel reported that RNG k-ϵ is (ANOVA) and regression analysis were carried out
better than k-ϵ when he studied the energy in order to determine the effects of process
separation and the flow phenomenon in a counter parameters and optimal factor settings. Finally,
flow vortex tube using CFD in Fluent. T. Farouk confirmation tests verified that Taguchi method
and B. Farouk introduced the large eddy simulation achieved optimization of counter flow Ranque–
(LES) technique to predict the flow fields and the Hilsch vortex tube performance with sufficient
associated temperature separation within a counter- accuracy.
flow vortex tube for several cold mass fractions.
However, most of the computations found in the Tanvir Farouk et al, [7] carried out
literature used simple or the first-order turbulence Simulation of gas species and temperature
models which are considered unsuitable for separation in the counter-flow Ranque–Hilsch
complex, compressible vortex tube flows. The vortex tube using the large eddy simulation
present work presents a two-dimensional numerical technique.A computational fluid dynamic model is
investigation of flow and temperature separation used to predict the species and temperature
behaviours inside a flow vortex tube.[3] separation within a counter flow Ranque–Hilsch
vortex tube. The large eddy simulation (LES)
III. EXPRIMENTAL & NUMRICAL technique was employed for predicting the gas flow
ANALYSIS and temperature fields and the species mass
From 1934, almost 200-215 articles are fractions (nitrogen and helium) in the vortex tube.
published on Ranque Hilsch vortex tube. Not all the A vortex tube with a circumferential inlet stream of
articles are directly related to our work, especially, nitrogen–helium mixture and an axial (cold) outlet
those articles which were focused on computational stream and a circumferential (hot) outlet stream
work. Many articles addressed experimental was considered. The temporal evolutions of the
findings and remaining discussed various theories axial, radial and azimuthal components of the
explaining energy separation phenomenon. In this velocity along with the temperature, pressure and
subsection, we are going to discuss only those mass density and species concentration fields
articles (experimental and/or theoretical work) within the vortex tube are simulated. Even though a
which are directly related to current work.[4] large temperature separation was observed, only a
very minimal gas separation occurred due to
Upendra Behera et al, [5] were carried out diffusion effects. Correlations between the
CFD analysis and experimental investigations fluctuating components of velocity, temperature
towards optimizing the parameters of Ranque– and species mass fraction were calculated to
Hilsch vortex tube. Computational fluid dynamics understand the separation mechanism. The inner
(CFD) and experimental studies are conducted core flow was found to have large values of eddy
towards the optimization of the Ranque–Hilsch heat flux and Reynolds’s stresses. Simulations were
vortex tubes. Different types of nozzle profiles and carried out for varying amounts of cold outlet mass
number of nozzles are evaluated by CFD analysis. flow rates. Performance curves (temperature
The swirl velocity, axial velocity and radial separation/gas separation versus cold outlet mass
velocity components as well as the flow patterns fraction) were obtained for a specific vortex tube
including secondary circulation flow have been with a given inlet mass flow rate.
evaluated. The optimum cold end diameter (dc) and
the length to diameter (L/D) ratios and optimum
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4. Rahul B Patela, Dr. V. N. Bartariab ,Tausif M Shaikhc / International Journal of Engineering
Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.
Fig. 1. Time averaged total temperature
contours for the vortex tube in the r–x plane
(case 1). Time averaging was performed between
0.4 and 0.8 s
Fig. 1. Schematic diagram of a counter-flow
Ranque–Hilsch vortex tube.
K. Dincer et al, [9] were carried out Experimental
Fig. 2. Time averaged helium mass fraction investigation of performance of hot cascade type
contours for the vortex tube in the r–x plane Ranque-Hilsch vortex tube and exergy analysis. In
(case 1). Time averaging was performed between this study, three Ranque-Hilsch vortex tubes were
0.4 and 0.8 s. used, which have 9 mm inside diameter and
length/diameter ratio was 15. Their performances
S. Eiamsa-ard [8] was carried out were examined as one of the classical RHVT and
Experimental investigation of energy separation in other was hot cascade type RHVT. Performance
a counter-flow Ranque–Hilsch vortex tube with analysis was according to temperature difference
multiple inlet snail entries. The energy/ between the hot outlet and the inlet (ΔThot). The
Temperature separation phenomenon and cooling ΔThot values of hot cascade type Ranque-Hilsch
efficiency characteristics in a counter-flow vortex tubes were greater than the ΔThot values of
Ranque–Hilsch vortex tube (RHVT) are classical RHVT, which were determined
experimentally studied. The ascertainment focuses experimentally. The total inlet exergy, total outlet
on the effects of the multiple inlet snail entries exergy, total lost exergy and exergy efficiency of
(N=1 to 4 nozzles), cold orifice diameter ratios hot stream were investigated by using experimental
(d/D=0.3 to 0.7) and inlet pressures (Pi=2.0 and 3.0 data. In both the classical RHVT and hot cascade
bar). The experiments using the conventional type RHVT, it was found that as fraction of cold
tangential nozzles (N=4), are also performed for flow increases the total lost exergy decreases. It
comparison. The experimental results reveal that was also found that, the hot cascade type RHVT
the RHVT with the snail entry provides greater cold more exergy efficiency of hot outlet than the
air temperature reduction and cooling efficiency classical RHVT. Excess ΔThot value of hot cascade
than those offered by the RHVT with the type Ranque-Hilsch vortex tube causes the excess
conventional tangential inlet nozzle under the same exergy efficiency of hot outlet.
cold mass fraction and supply inlet pressure. The
increase in the nozzle number and the supply H.M. Skye et al, [10] were carried out
pressure leads to the rise of the swirl/vortex Comparison of CFD analysis to empirical data in a
intensity and thus the energy separation in the tube. Commercial vortex tube. This paper presents a
comparison between the performance predicted by
a computational fluid dynamic (CFD) model and
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5. Rahul B Patel, Dr. V. N. Bartaria , Tausif M Shaikh / International Journal of Engineering
Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.1359-1363
experimental measurements taken using a [2] K. Dincer et al, were carried out
commercially available vortex tube. Specifically, ―Experimental investigation of the
the measured exit temperatures into and out of the performance of a Ranque–Hilsch Vortex
vortex tube are compared with the CFD model. The tube with regard to a plug located at the
data and the model are both verified using global hot outlet‖.
mass and energy balances. The CFD model is a [3] Prof. R. K. Sahoo et al, were carried out
two-dimensional (2D) steady axisymmetric model ―Numerical Analysis in Ranque-Hilsch
(with swirl) that utilizes both the standard and Vortex tube.‖
renormalization group (RNG) k-epsilon turbulence [4] Sachin U. Nimbalkar et al, were carried
models. While CFD has been used previously to out ―Quantitative observations on multiple
understand the fluid behavior internal to the vortex flow structures inside Ranque Hilsch
tube, it has not been applied as a predictive model vortex tube.‖
of the vortex tube in order to develop a design tool [5] Upendra Behera et al, were carried out
that can be used with confidence over a range of ―CFD analysis and experimental
operating conditions and geometries. The objective investigations towards optimizing the
of this paper is the demonstration of the successful parameters of Ranque–Hilsch vortex
use of CFD in this regard, thereby providing a tube.‖
powerful tool that can be used to optimize vortex [6] Ahmet Murat Pinar et al, were carried out
tube design as well as assess its utility in the ―Optimization of counter flow Ranque–
context of new applications. Hilsch vortex tube performance using
Taguchi method.‖
[7] Tanvir Farouk et al, were carried out
―Simulation of gas species and
temperature separation in the counter-flow
Ranque–Hilsch vortex tube using the large
eddy simulation technique.‖
[8]. S.Eiamsa-ard was carried out
―Experimental investigation of energy
separation in a Counter- flow Ranque–
Hilsch vortex tube with multiple inlet snail
entries.‖
Fig. 3. Picture of vortex tube used for [9] .K. Dincer et al, were carried out
experiment. ―Experimental investigation of
performance of hot cascade type Ranque-
IV. CONCLUSION:- Hilsch vortex tube and exergy analysis.‖
The issue concerned in all explanations is [10]. H.M. Skye et al, were carried out
the energy transfer between different layers. When Comparison of CFD analysis to empirical
little energy is transferred from the inner flow to data in a Commercial vortex tube.
the outer flow, the temperature drop of cold air can
be considered to be the result of sudden expansion
near the entrance, and the temperature rise of hot
air might be the result of friction of the multi-
circulation near the hot exit. Therefore, clarification
of the energy transfer between different layers is a
useful approach in the investigation of the vortex
tube. Clear understanding of the flow structure
inside the vortex tube is required for further
investigation, especially the region near the
entrance in which sudden expansion is considered
as the governing process and the region near the
exit in which multi-circulation may be formed.
From the above study I am much more interested to
work on Experimental & Numerical investigation
of Ranque-Hilsch vortex tube using CFD.
V. REFERENCES
[1] Yunpeng Xue et al, were carried out ―A
critical review of temperature separation
in a vortex tube‖.
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