This document summarizes a study on fluid flow and heat transfer from multiple circular jets impinging on a flat plate. Computational fluid dynamics simulations were performed using the k-ω SST turbulence model to analyze the flow structure and pressure distribution. Experiments using an oil-lampblack visualization technique were also conducted for comparison. The simulations examined the effects of varying the jet-to-plate spacing ratio (h/d) from 0.5 to 4 and the Reynolds number from 9075 to 13624. It was observed that the flow topology was independent of Reynolds number but depended strongly on h/d. Primary pressure peaks occurred at stagnation points and secondary peaks at wall jet interaction regions.
Computational analysis of centrifugal compressor with grooves on casingIAEME Publication
This document summarizes the results of a computational fluid dynamics analysis of a centrifugal compressor with grooves on the casing. Three cases were analyzed: without grooves, with two grooves, and with three grooves. For the case with two grooves, the passage wake area (region of low velocity flow) near the casing was reduced, velocity in this area increased, and pressure ratio improved at all flow coefficients compared to the no groove case. However, for the case with three grooves, while the passage wake area was further reduced, the velocity and pressure in this area decreased due to greater leakage flow through the grooves, resulting in a reduction in pressure ratio. Overall, the two groove configuration provided better performance
Flow Investigation inside A Curved Square DuctIJERA Editor
This paper presents the results of an experimental work with measurement of wall static pressure of 90°C shaped Curved duct. The test duct is made up of transparent perspex sheets to facilitate the flow visualization study. The duct has an inlet to exit area ratio of 1.0 with centerline distance of 750 mm. The inlet aspect ratio of the test duct has been fixed at 1.0. The velocities for the proposed investigations are to be measured by using a Pitot tube.Wall pressures are measured with the help of an inclinedmanometer with the inclination of 35°. The manometer had two tubes emanating from it: one left open to the atmosphere and the other connected to the steel pipes attached to the four walls of the curved duct. The difference in the readings helped us calculate the static pressure and thereby the normalized pressure. Wall pressure distribution along the curved and parallel walls of the duct at 0°, 22.5°, 45°, 67.5° and 90° measuring sections was measured. All the experimental data has been processed by an Intel i3 CPU, 3 GB RAM PC and analyzed to give the distribution of static pressure in the square duct.The main purpose of this investigation is to show the development of secondary flow which happens when the flow takes place through the bend in the curvature. This secondary flow arises as a result of a centrifugal force acting when the flow moves through the bend. The investigation is carried out at three different velocities 20 m/s, 40 m/s and 60 m/s. The distribution of normalized pressure which is the ratio of static pressure to the dynamic pressure is mapped and shown in the form of contours by using the software package SURFER.The trend of wall static pressure development on the walls of C shaped duct shows that as the flow proceeds towards the curvature, there exists a high pressure gradient between the outside face and inside face due the centrifugal force acting along the curvature. This shows the bulk shifting of flow towards the inside face. This is due to the generation of secondary motion in a plane perpendicular to the primary flow.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
This document summarizes a study that used computational fluid dynamics (CFD) to analyze the effects of suction and blowing techniques on the performance of an S-shaped diffuser. The study found that suction at the outer inflection plane improved pressure recovery by around 8%, while blowing at the inner inflection plane provided only marginal improvement of around 3%. The CFD model used a k-ε turbulence model and was validated against experimental data, showing reasonably good agreement. Key performance parameters like pressure gain coefficient and non-uniformity index were calculated and used to evaluate the diffuser performance with and without suction and blowing.
1) The document describes an experimental study on the aerodynamic characteristics of basic airfoils at low Reynolds numbers between 2.9×104 and 7.2×104.
2) Wind tunnel experiments were conducted on airfoil models including a NACA0015, flat plate, and modified flat plates with different leading and trailing edge geometries. Surface pressure measurements were taken at varying angles of attack.
3) Preliminary results showed the importance of sharp leading edges for low Reynolds number flight and the influence of airfoil geometry on aerodynamic characteristics like pressure coefficient.
Effect of tip clearance on a centrifugal compressorIAEME Publication
This document summarizes a computational analysis of the effect of tip clearance on a low-speed centrifugal compressor. A centrifugal compressor impeller with three tip clearances (0%, 2%, and 5% of blade height) was examined at five flow coefficients using computational fluid dynamics software. The results found that static and total pressure decreased with increasing tip clearance. Blade loading charts and pressure/velocity contours showed lower pressures and velocities on the blade surfaces with larger tip clearances. In conclusion, tip clearances were found to increase losses in the centrifugal compressor.
The document summarizes an experimental study that investigated the wind load on hexagonal cylinders. Static pressure distributions were measured on single and paired hexagonal cylinders in a wind tunnel at various wind speeds and angles of attack. Lower drag and lift forces were observed for hexagonal cylinders compared to square cylinders, approaching the lower values seen for circular cylinders. It was concluded that hexagonal cylinders experience significantly lower wind loads than square cylinders of the same width.
Poor blade curvature a contributor in the loss of performance in the compre...Alexander Decker
The document discusses how the curvature of compressor blades in a gas turbine system can contribute to loss of performance. Three blade sets with different curvatures (20°, 35°, 50°) were tested in a wind tunnel. The results showed that blades with higher curvature had higher points of flow separation and vortex height on the trailing edge, indicating poorer performance. Greater blade curvature leads to a higher possibility of issues like flow separation, turbulence, reduced pressure rise, and compressor stalling, all of which reduce the efficiency and power of the gas turbine system.
Computational analysis of centrifugal compressor with grooves on casingIAEME Publication
This document summarizes the results of a computational fluid dynamics analysis of a centrifugal compressor with grooves on the casing. Three cases were analyzed: without grooves, with two grooves, and with three grooves. For the case with two grooves, the passage wake area (region of low velocity flow) near the casing was reduced, velocity in this area increased, and pressure ratio improved at all flow coefficients compared to the no groove case. However, for the case with three grooves, while the passage wake area was further reduced, the velocity and pressure in this area decreased due to greater leakage flow through the grooves, resulting in a reduction in pressure ratio. Overall, the two groove configuration provided better performance
Flow Investigation inside A Curved Square DuctIJERA Editor
This paper presents the results of an experimental work with measurement of wall static pressure of 90°C shaped Curved duct. The test duct is made up of transparent perspex sheets to facilitate the flow visualization study. The duct has an inlet to exit area ratio of 1.0 with centerline distance of 750 mm. The inlet aspect ratio of the test duct has been fixed at 1.0. The velocities for the proposed investigations are to be measured by using a Pitot tube.Wall pressures are measured with the help of an inclinedmanometer with the inclination of 35°. The manometer had two tubes emanating from it: one left open to the atmosphere and the other connected to the steel pipes attached to the four walls of the curved duct. The difference in the readings helped us calculate the static pressure and thereby the normalized pressure. Wall pressure distribution along the curved and parallel walls of the duct at 0°, 22.5°, 45°, 67.5° and 90° measuring sections was measured. All the experimental data has been processed by an Intel i3 CPU, 3 GB RAM PC and analyzed to give the distribution of static pressure in the square duct.The main purpose of this investigation is to show the development of secondary flow which happens when the flow takes place through the bend in the curvature. This secondary flow arises as a result of a centrifugal force acting when the flow moves through the bend. The investigation is carried out at three different velocities 20 m/s, 40 m/s and 60 m/s. The distribution of normalized pressure which is the ratio of static pressure to the dynamic pressure is mapped and shown in the form of contours by using the software package SURFER.The trend of wall static pressure development on the walls of C shaped duct shows that as the flow proceeds towards the curvature, there exists a high pressure gradient between the outside face and inside face due the centrifugal force acting along the curvature. This shows the bulk shifting of flow towards the inside face. This is due to the generation of secondary motion in a plane perpendicular to the primary flow.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
This document summarizes a study that used computational fluid dynamics (CFD) to analyze the effects of suction and blowing techniques on the performance of an S-shaped diffuser. The study found that suction at the outer inflection plane improved pressure recovery by around 8%, while blowing at the inner inflection plane provided only marginal improvement of around 3%. The CFD model used a k-ε turbulence model and was validated against experimental data, showing reasonably good agreement. Key performance parameters like pressure gain coefficient and non-uniformity index were calculated and used to evaluate the diffuser performance with and without suction and blowing.
1) The document describes an experimental study on the aerodynamic characteristics of basic airfoils at low Reynolds numbers between 2.9×104 and 7.2×104.
2) Wind tunnel experiments were conducted on airfoil models including a NACA0015, flat plate, and modified flat plates with different leading and trailing edge geometries. Surface pressure measurements were taken at varying angles of attack.
3) Preliminary results showed the importance of sharp leading edges for low Reynolds number flight and the influence of airfoil geometry on aerodynamic characteristics like pressure coefficient.
Effect of tip clearance on a centrifugal compressorIAEME Publication
This document summarizes a computational analysis of the effect of tip clearance on a low-speed centrifugal compressor. A centrifugal compressor impeller with three tip clearances (0%, 2%, and 5% of blade height) was examined at five flow coefficients using computational fluid dynamics software. The results found that static and total pressure decreased with increasing tip clearance. Blade loading charts and pressure/velocity contours showed lower pressures and velocities on the blade surfaces with larger tip clearances. In conclusion, tip clearances were found to increase losses in the centrifugal compressor.
The document summarizes an experimental study that investigated the wind load on hexagonal cylinders. Static pressure distributions were measured on single and paired hexagonal cylinders in a wind tunnel at various wind speeds and angles of attack. Lower drag and lift forces were observed for hexagonal cylinders compared to square cylinders, approaching the lower values seen for circular cylinders. It was concluded that hexagonal cylinders experience significantly lower wind loads than square cylinders of the same width.
Poor blade curvature a contributor in the loss of performance in the compre...Alexander Decker
The document discusses how the curvature of compressor blades in a gas turbine system can contribute to loss of performance. Three blade sets with different curvatures (20°, 35°, 50°) were tested in a wind tunnel. The results showed that blades with higher curvature had higher points of flow separation and vortex height on the trailing edge, indicating poorer performance. Greater blade curvature leads to a higher possibility of issues like flow separation, turbulence, reduced pressure rise, and compressor stalling, all of which reduce the efficiency and power of the gas turbine system.
This document summarizes an experimental study on jet impingement cooling of a ribbed surface with holes. The researchers varied parameters like heat flux, nozzle-to-plate distance ratio (H/d ratio), and Reynolds number. They measured temperatures at different locations and calculated heat transfer coefficients and Nusselt numbers. Key findings include that heat transfer increased with decreasing H/d ratio and increasing heat flux. Nusselt numbers generally increased with Reynolds number and heat flux. The presence of holes and enclosure affected flow patterns and temperature readings.
CFD Simulation of Swirling Effect in S-Shaped Diffusing Duct by Swirl Angle o...IOSR Journals
This document describes a computational fluid dynamics (CFD) simulation of swirling flow through an S-shaped diffusing duct with a 10 degree swirl angle. The study models airflow through a duct with an area ratio of 1.9, length of 300mm, and turning angle of 22.5 degrees. Simulations were conducted for uniform inlet flow and swirling inlet flow clockwise and counter-clockwise. Results show that swirling flow improves static pressure recovery over uniform flow. Clockwise swirling flow provided the highest pressure recovery and most uniform exit flow. Turbulence intensity and secondary flows increased through the duct but did not exceed 15% of inlet velocity.
Flow Development through a Duct and a Diffuser Using CFDIJERA Editor
In the present paper an extensive study of rectangular cross-sectioned C-duct and C-diffuser is made by the help of 2-D mean velocity contours. Study of flow characteristics through constant area duct is a fundamental research area of basic fluid mechanics since the concepts of potential flow and frictional losses in conduit flow were established. C-ducts are used in aircraft intakes, combustors, internal cooling systems of gas turbines, ventilation ducts, wind tunnels etc., while diffuser is mechanical device usually made in the form of a gradual conical expander intended to raise the static pressure of the fluid flowing through it. Flow through curved ducts is more complex compared to straight duct due to the curvature of the duct axis and centrifugal forces are induced on the flowing fluid resulting in the development of secondary motion (normal to the primary flow direction) which is manifested in the form of a pair of contra-rotating vortices. For a diffuser in addition to the secondary flow, the diverging flow passage, which causes an adverse stream wise pressure gradient, can lead to flow separation. The combined effect may result n non uniformity of total pressure and total pressure loss at the exit. A comparative study of different turbulent models available in the Fluent using y as guidance in selecting the appropriate grid configuration and turbulence models are done. Standard k-ε model and RSM models are used to solve the closure problem for both the constant area duct and the diffuser. It has been observed that the Standard k-e model predicts the flow through the constant area duct and the diffuser within a reasonable domain ofthe y range.
IRJET- Static Pressure Distribution on Plane Flat Plate Surface by Air Or...IRJET Journal
The document presents an experimental study on the static pressure distribution on a flat plate surface due to air jet impingement from a circular orifice. Key findings from the study include:
1) The static pressure coefficient (Cp) is highest at the stagnation point where the jet first impinges on the plate (x/d = 0) and decreases with increasing longitudinal distance (x/d) from the impingement point.
2) Cp values decrease with increasing nozzle to plate distance (Z/d) as the jet spreads over a larger surface area.
3) Within the range of Reynolds numbers studied (6000-40000), Reynolds number does not influence the static pressure distribution.
AJK2011-03023 (Conference Paper DR) Modelling Multiphase Jet Flows for High V...David Ryan
This document summarizes CFD simulations of flow inside an industrial static mixer called a Sonolator. Single-phase steady-state simulations were performed for three mass flow rates through a fixed nozzle orifice. Streamline data was used to calculate residence times and turbulent energy dissipation rates, which can provide insight into droplet breakup for emulsification processes. Validation was done against experimental discharge coefficients and predicted droplet sizes may depend on inlet conditions for multiphase mixtures.
This document discusses the history and importance of quantitative metallography and microstructural analysis. It describes how 30 years ago, characterizing microstructures was largely qualitative, with visual ratings being the main approach. Over time, the field developed stereology techniques to provide more precise and reproducible quantification, such as using point counting to determine phase proportions rather than subjective visual ratings. The document gives examples of how point counting and other stereology methods work and their benefits over older qualitative approaches.
Drag Optimization of Bluff Bodies using CFD for Aerodynamic Applicationsijceronline
This paper deals with the optimization of bluff bodies and analysis of fluid flow behaviour around bodies using CFD. Three test cases of bluff bodies; mainly two-dimensional rectangular body, radial rectangular shape and bullet shaped body were considered in this paper. Their shapes were optimised to achieve aerodynamic body shape using drag coefficient as main criteria. The other aerodynamic characteristics like formation of different eddy loops due to eddy viscosity, lift force coefficient and pressure force with Mach number were also investigated. It is concluded that aerodynamically; bullet shaped body is best among all the cases
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.
CFD and EXPERIMENTAL ANALYSIS of VORTEX SHEDDING BEHIND D-SHAPED CYLINDERAM Publications
The flow around bluff bodies is an area of great research of scientists for several years. Vortex shedding is
one of the most challenging phenomenon in turbulent flows. This phenomenon was first studied by Strouhal. Many
researchers have modeled the various objects as cylinders with different cross-sections among which square and
circular cylinders were the most interested sections to study the vortex shedding phenomenon. The Vortex Shedding
frequency depends on different aspects of the flow field such as the end conditions, blockage ratio of the flow passage,
and width to height ratio. This case studies the wave development behind a D-Shaped cylinder, at different Reynolds
numbers, for which we expect a vortex street in the wake of the D-Shaped cylinder, the well known as von Kármán
Street. This body typically serves some vital operational function in aerodynamic. In circular cylinder flow separation
point changes with Reynolds number but in D-Shaped cylinder there is fix flow separation point. So there is more
wake steadiness in D-Shaped cylinder as compared to Circular cylinder and drag reduction because of wake
steadiness.In the present work CFD simulation is carried out for flow past a D-Shaped cylinder to see the wake
behavior. The Reynolds number regime currently studied corresponds to low Reynolds number, laminar and
nominally two-dimensional wake. The fluid domain is a two-dimensional plane with a D-Shaped cylinder of
dimensions B=90mm, H=80mm and L=200mm. CFD calculations of the 2-D flow past the D-Shaped cylinder are
presented and results are validated by comparing with Experimental results of pressure distribution on cylinder
surface. The experimentation is carried out using small open type wind tunnel. The flow visualization is done by
smoke visualization technique. Results are presented for various B/H ratios and Reynolds numbers. The variation of
Strouhal number with Reynolds number is found from the analysis. The focus of the present research is on reducing
the wake unsteadiness.
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
EXPERIMENTAL and ANALYTICAL ANALYSIS of FLOW PAST D-SHAPED CYLINDERAM Publications
The study of flow past the bluff body is very important in aerodynamics. The D-Shaped cylinder is one of the
bluff bodies which serve some vital operational function in aerodynamic. So it is necessary to study the flow past the DShaped
cylinder. In this paper the flow past D-Shaped cylinder of dimensions B=90mm, H=80mm, and L=200mm is
studied experimentally and analytically. The analytical results are validated with experimental results. The flow
parameter drag co-efficient is calculated for different Reynolds number using Drag co-efficient relation and results of
drag co-efficient are validated with experimental results. Based on the experimental and analytical results, the drag coefficient
of circular cylinder and D-Shaped cylinder are compared. The Strouhal number is calculated using Strouhal
number co-relation for different Reynolds number and results of Strouhal number are validated with previous results
from literature. The experimentation is carried in small open type wind tunnel. The Reynolds number regime currently
studied corresponds to low Reynolds number. The present research involves the calculation of drag co-efficient for DShaped
cylinder. This experiment is based on existing wind tunnel that is already developed. The focus of the present
research is on finding the drag co-efficient both by experimentally and analytically.
This document summarizes an experiment studying the effect of perforated ribs as vortex generators on air flow through a square channel. The experiment measured friction factor ratio and pressure drop for different configurations of perforated ribs, varying the ribs' aspect ratio and pitch-to-height ratio. Tests were run for aspect ratios of 2, 3, and 5 and pitch-to-height ratios of 4, 8, 12, and 16 over a Reynolds number range of 8,000 to 24,000. The results showed that friction factor ratio increased with Reynolds number, as higher flow velocities generated more vortices and turbulence, increasing pressure drop.
The document summarizes a numerical investigation of fluid flow around a surface-mounted pyramid. Key findings include:
1) There exists an optimum apex angle and attack angle that results in maximum turbulent intensity and reattachment distance.
2) For the same height and volume, a square-based prism has a longer reattachment distance compared to other shapes.
3) Computed velocity profiles at the rear of the pyramid show higher backflow intensity toward the bottom of the domain.
Iaetsd study and experimental analysis of linear and non linear behaviour ofIaetsd Iaetsd
The document describes an experimental study on the linear and non-linear behavior of pipe bends with ovality. Various pipe bend schedules including SCH 40 long radius, SCH 40 short radius, and SCH 80 short radius bends were tested under in-plane and out-of-plane bending moments both with and without internal pressure. Displacement and percentage change in ovality were measured in the intrados, crown, and extrados regions. The displacement in the intrados and extrados increased linearly with load. Allowable limit loads and ovality are suggested to avoid pipe rejection due to insufficient wall thickness. Mathematical and software results were compared to experimental results to optimize output.
Study of shape of intermediate sill on the design of stilling basin modeleSAT Publishing House
This study examined the effect of intermediate sill shape on stilling basin design for pipe outlets. Experiments were conducted on four stilling basin models with different intermediate sill shapes (triangular, rectangular, square) to dissipate flow energy from a pipe outlet. The square intermediate sill produced the lowest scour indices, indicating best performance. Compared to the standard USBR VI model, the developed square sill model improved performance by 47-58% depending on flow conditions. In conclusion, intermediate sill shape significantly impacts stilling basin performance, with a square sill producing the most efficient design according to experimental results.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
This document summarizes a study that used computational fluid dynamics (CFD) to simulate the performance of a single-stage axial flow compressor with varying blade aspect ratios of 1, 2, and 3. The study found that compressor performance is affected by aspect ratio, with the best operating conditions occurring between ratios of 2 and 3. Streamline analyses were conducted to analyze pressure and velocity distributions within the compressor and determine how parameters like mach number varied across different aspect ratio configurations. Modal analyses were also performed to study frequency responses at different vibration modes.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document presents an efficient soft set approach for mining association rules that uses an initial support constraint to filter out false frequent items and rarely occurring items. This improves the structure of the dataset and results in faster, more accurate results that use less memory than previous approaches. The improved dataset is transformed into a Boolean-valued information system, allowing it to be represented as a soft set. Association rules are then mined between sets of co-occurring parameters using soft set theory. Experimental results show this approach produces strong association rules faster with the same accuracy using less memory space.
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 describes a system for measuring and controlling water temperature and flow for testing thermal discharge models from power plants. The system uses digital temperature sensors, flow meters, and level sensors along with a PID controller. Measurements are transmitted wirelessly and processed using MATLAB software. Experimental results show the system can control temperature and flow rate to desired set points, helping evaluate environmental impacts of power plant discharge and meet regulatory standards.
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 an experimental study on jet impingement cooling of a ribbed surface with holes. The researchers varied parameters like heat flux, nozzle-to-plate distance ratio (H/d ratio), and Reynolds number. They measured temperatures at different locations and calculated heat transfer coefficients and Nusselt numbers. Key findings include that heat transfer increased with decreasing H/d ratio and increasing heat flux. Nusselt numbers generally increased with Reynolds number and heat flux. The presence of holes and enclosure affected flow patterns and temperature readings.
CFD Simulation of Swirling Effect in S-Shaped Diffusing Duct by Swirl Angle o...IOSR Journals
This document describes a computational fluid dynamics (CFD) simulation of swirling flow through an S-shaped diffusing duct with a 10 degree swirl angle. The study models airflow through a duct with an area ratio of 1.9, length of 300mm, and turning angle of 22.5 degrees. Simulations were conducted for uniform inlet flow and swirling inlet flow clockwise and counter-clockwise. Results show that swirling flow improves static pressure recovery over uniform flow. Clockwise swirling flow provided the highest pressure recovery and most uniform exit flow. Turbulence intensity and secondary flows increased through the duct but did not exceed 15% of inlet velocity.
Flow Development through a Duct and a Diffuser Using CFDIJERA Editor
In the present paper an extensive study of rectangular cross-sectioned C-duct and C-diffuser is made by the help of 2-D mean velocity contours. Study of flow characteristics through constant area duct is a fundamental research area of basic fluid mechanics since the concepts of potential flow and frictional losses in conduit flow were established. C-ducts are used in aircraft intakes, combustors, internal cooling systems of gas turbines, ventilation ducts, wind tunnels etc., while diffuser is mechanical device usually made in the form of a gradual conical expander intended to raise the static pressure of the fluid flowing through it. Flow through curved ducts is more complex compared to straight duct due to the curvature of the duct axis and centrifugal forces are induced on the flowing fluid resulting in the development of secondary motion (normal to the primary flow direction) which is manifested in the form of a pair of contra-rotating vortices. For a diffuser in addition to the secondary flow, the diverging flow passage, which causes an adverse stream wise pressure gradient, can lead to flow separation. The combined effect may result n non uniformity of total pressure and total pressure loss at the exit. A comparative study of different turbulent models available in the Fluent using y as guidance in selecting the appropriate grid configuration and turbulence models are done. Standard k-ε model and RSM models are used to solve the closure problem for both the constant area duct and the diffuser. It has been observed that the Standard k-e model predicts the flow through the constant area duct and the diffuser within a reasonable domain ofthe y range.
IRJET- Static Pressure Distribution on Plane Flat Plate Surface by Air Or...IRJET Journal
The document presents an experimental study on the static pressure distribution on a flat plate surface due to air jet impingement from a circular orifice. Key findings from the study include:
1) The static pressure coefficient (Cp) is highest at the stagnation point where the jet first impinges on the plate (x/d = 0) and decreases with increasing longitudinal distance (x/d) from the impingement point.
2) Cp values decrease with increasing nozzle to plate distance (Z/d) as the jet spreads over a larger surface area.
3) Within the range of Reynolds numbers studied (6000-40000), Reynolds number does not influence the static pressure distribution.
AJK2011-03023 (Conference Paper DR) Modelling Multiphase Jet Flows for High V...David Ryan
This document summarizes CFD simulations of flow inside an industrial static mixer called a Sonolator. Single-phase steady-state simulations were performed for three mass flow rates through a fixed nozzle orifice. Streamline data was used to calculate residence times and turbulent energy dissipation rates, which can provide insight into droplet breakup for emulsification processes. Validation was done against experimental discharge coefficients and predicted droplet sizes may depend on inlet conditions for multiphase mixtures.
This document discusses the history and importance of quantitative metallography and microstructural analysis. It describes how 30 years ago, characterizing microstructures was largely qualitative, with visual ratings being the main approach. Over time, the field developed stereology techniques to provide more precise and reproducible quantification, such as using point counting to determine phase proportions rather than subjective visual ratings. The document gives examples of how point counting and other stereology methods work and their benefits over older qualitative approaches.
Drag Optimization of Bluff Bodies using CFD for Aerodynamic Applicationsijceronline
This paper deals with the optimization of bluff bodies and analysis of fluid flow behaviour around bodies using CFD. Three test cases of bluff bodies; mainly two-dimensional rectangular body, radial rectangular shape and bullet shaped body were considered in this paper. Their shapes were optimised to achieve aerodynamic body shape using drag coefficient as main criteria. The other aerodynamic characteristics like formation of different eddy loops due to eddy viscosity, lift force coefficient and pressure force with Mach number were also investigated. It is concluded that aerodynamically; bullet shaped body is best among all the cases
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.
CFD and EXPERIMENTAL ANALYSIS of VORTEX SHEDDING BEHIND D-SHAPED CYLINDERAM Publications
The flow around bluff bodies is an area of great research of scientists for several years. Vortex shedding is
one of the most challenging phenomenon in turbulent flows. This phenomenon was first studied by Strouhal. Many
researchers have modeled the various objects as cylinders with different cross-sections among which square and
circular cylinders were the most interested sections to study the vortex shedding phenomenon. The Vortex Shedding
frequency depends on different aspects of the flow field such as the end conditions, blockage ratio of the flow passage,
and width to height ratio. This case studies the wave development behind a D-Shaped cylinder, at different Reynolds
numbers, for which we expect a vortex street in the wake of the D-Shaped cylinder, the well known as von Kármán
Street. This body typically serves some vital operational function in aerodynamic. In circular cylinder flow separation
point changes with Reynolds number but in D-Shaped cylinder there is fix flow separation point. So there is more
wake steadiness in D-Shaped cylinder as compared to Circular cylinder and drag reduction because of wake
steadiness.In the present work CFD simulation is carried out for flow past a D-Shaped cylinder to see the wake
behavior. The Reynolds number regime currently studied corresponds to low Reynolds number, laminar and
nominally two-dimensional wake. The fluid domain is a two-dimensional plane with a D-Shaped cylinder of
dimensions B=90mm, H=80mm and L=200mm. CFD calculations of the 2-D flow past the D-Shaped cylinder are
presented and results are validated by comparing with Experimental results of pressure distribution on cylinder
surface. The experimentation is carried out using small open type wind tunnel. The flow visualization is done by
smoke visualization technique. Results are presented for various B/H ratios and Reynolds numbers. The variation of
Strouhal number with Reynolds number is found from the analysis. The focus of the present research is on reducing
the wake unsteadiness.
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
EXPERIMENTAL and ANALYTICAL ANALYSIS of FLOW PAST D-SHAPED CYLINDERAM Publications
The study of flow past the bluff body is very important in aerodynamics. The D-Shaped cylinder is one of the
bluff bodies which serve some vital operational function in aerodynamic. So it is necessary to study the flow past the DShaped
cylinder. In this paper the flow past D-Shaped cylinder of dimensions B=90mm, H=80mm, and L=200mm is
studied experimentally and analytically. The analytical results are validated with experimental results. The flow
parameter drag co-efficient is calculated for different Reynolds number using Drag co-efficient relation and results of
drag co-efficient are validated with experimental results. Based on the experimental and analytical results, the drag coefficient
of circular cylinder and D-Shaped cylinder are compared. The Strouhal number is calculated using Strouhal
number co-relation for different Reynolds number and results of Strouhal number are validated with previous results
from literature. The experimentation is carried in small open type wind tunnel. The Reynolds number regime currently
studied corresponds to low Reynolds number. The present research involves the calculation of drag co-efficient for DShaped
cylinder. This experiment is based on existing wind tunnel that is already developed. The focus of the present
research is on finding the drag co-efficient both by experimentally and analytically.
This document summarizes an experiment studying the effect of perforated ribs as vortex generators on air flow through a square channel. The experiment measured friction factor ratio and pressure drop for different configurations of perforated ribs, varying the ribs' aspect ratio and pitch-to-height ratio. Tests were run for aspect ratios of 2, 3, and 5 and pitch-to-height ratios of 4, 8, 12, and 16 over a Reynolds number range of 8,000 to 24,000. The results showed that friction factor ratio increased with Reynolds number, as higher flow velocities generated more vortices and turbulence, increasing pressure drop.
The document summarizes a numerical investigation of fluid flow around a surface-mounted pyramid. Key findings include:
1) There exists an optimum apex angle and attack angle that results in maximum turbulent intensity and reattachment distance.
2) For the same height and volume, a square-based prism has a longer reattachment distance compared to other shapes.
3) Computed velocity profiles at the rear of the pyramid show higher backflow intensity toward the bottom of the domain.
Iaetsd study and experimental analysis of linear and non linear behaviour ofIaetsd Iaetsd
The document describes an experimental study on the linear and non-linear behavior of pipe bends with ovality. Various pipe bend schedules including SCH 40 long radius, SCH 40 short radius, and SCH 80 short radius bends were tested under in-plane and out-of-plane bending moments both with and without internal pressure. Displacement and percentage change in ovality were measured in the intrados, crown, and extrados regions. The displacement in the intrados and extrados increased linearly with load. Allowable limit loads and ovality are suggested to avoid pipe rejection due to insufficient wall thickness. Mathematical and software results were compared to experimental results to optimize output.
Study of shape of intermediate sill on the design of stilling basin modeleSAT Publishing House
This study examined the effect of intermediate sill shape on stilling basin design for pipe outlets. Experiments were conducted on four stilling basin models with different intermediate sill shapes (triangular, rectangular, square) to dissipate flow energy from a pipe outlet. The square intermediate sill produced the lowest scour indices, indicating best performance. Compared to the standard USBR VI model, the developed square sill model improved performance by 47-58% depending on flow conditions. In conclusion, intermediate sill shape significantly impacts stilling basin performance, with a square sill producing the most efficient design according to experimental results.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
This document summarizes a study that used computational fluid dynamics (CFD) to simulate the performance of a single-stage axial flow compressor with varying blade aspect ratios of 1, 2, and 3. The study found that compressor performance is affected by aspect ratio, with the best operating conditions occurring between ratios of 2 and 3. Streamline analyses were conducted to analyze pressure and velocity distributions within the compressor and determine how parameters like mach number varied across different aspect ratio configurations. Modal analyses were also performed to study frequency responses at different vibration modes.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document presents an efficient soft set approach for mining association rules that uses an initial support constraint to filter out false frequent items and rarely occurring items. This improves the structure of the dataset and results in faster, more accurate results that use less memory than previous approaches. The improved dataset is transformed into a Boolean-valued information system, allowing it to be represented as a soft set. Association rules are then mined between sets of co-occurring parameters using soft set theory. Experimental results show this approach produces strong association rules faster with the same accuracy using less memory space.
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 describes a system for measuring and controlling water temperature and flow for testing thermal discharge models from power plants. The system uses digital temperature sensors, flow meters, and level sensors along with a PID controller. Measurements are transmitted wirelessly and processed using MATLAB software. Experimental results show the system can control temperature and flow rate to desired set points, helping evaluate environmental impacts of power plant discharge and meet regulatory standards.
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
A Review: Significant Research on Time And Frequency Synchronization In MIMO ...IJERA Editor
This paper proposes a fast and dependable procedure for timing and frequency synchronization of multiple-input
multiple- output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. Orthogonal frequency
division multiplexing (OFDM) could be a outstanding technique for high info rate remote transmission. The
execution of OFDM framework is exceptionally touchy to transporter repeat Offset (CFO) that presents between
bearer electric resistances (ICI). Multi data multi yield frame work used for increasing various qualities increase
and limit of the framework. During this space repeat synchronization in associate OFDM framework is
contemplated and gave past work OFDM framework.
Analysis of a Compessor Rotor using Finite Element AnalysisIJERA Editor
This document analyzes the stresses on an axial compressor rotor using finite element analysis. It summarizes the modeling, analysis, and results of analyzing an existing 18-blade rotor model using two materials (chromium steel and titanium alloy), as well as modified 16-blade and 14-blade models using the same materials. Von Mises stresses were lowest for the 14-blade titanium alloy model. The conclusion is that titanium alloy provides better performance than chromium steel, and reducing the number of blades from 18 to 14 further reduces stresses.
Congestion Control in Wireless Sensor Networks: A surveyIJERA Editor
Congestion is a major problem in almost all kinds of wireless networks such as mobile ad-hoc networks; wireless
sensor networks (WSNs). There are variety of applications of WSN such as defense, temperature monitoring,
health monitoring. Congestion occurs in the sensor network because of limited resources such as low processing
power of the sensor node. As all the sensor nodes are battery powered. Hence, congestion in the sensor network
results in waste of energy of sensor nodes. All the layers of protocol suite of the network can be involved in the
congestion control process. This paper gives a brief idea about various congestion control methods. In some of
the schemes, cross-layer design is applied for better results.
Validation of the Newly Developed Fabric Feel Tester for Its Accuracy and Rep...IJERA Editor
The present paper deals with a comprehensive study of reproducibility of the newly developed instrument to
study fabric handle characteristics using extraction principle. As reported earlier that a new nozzle extraction
method for objective measurement of fabric handle characteristics has been developed. The force exerted by the
fabric being drawn out of the nozzle is known as extraction force and the force exerted by the fabric at the side
wall of the nozzle is known as radial force. A few fabric samples have been tested on this newly developed
instrument and the effect of numbers of tests has been studied. It has been observed that minimum five samples
of a fabric test in this instrument gives lower standard deviation of the test results. Also the overall deviations of
results justified the reproducibility of the instrument and hence the said instrument if validated for its testing
parameters.
Natural Disaster (Tsunami) and Its Socio Economic and Environmental Impact – ...IJERA Editor
Natural Disaster (Tsunami) and Its Socio Economic And Environmental Impact – A Case Study Of
Kanyakumari Coast”. Kanyakumari is the southernmost district of Tamil Nadu. The software Arc Gis are used
to demarcate the Natural Disaster ( Tsunami) and its socio Economic and Environment Impact. The district lies
between longitudes is 77˚15‟ E 77˚36‟ Eastern longitudes. The Latitudes is 8˚03‟ N to 8˚35‟ Northern
latitudes.The District is bound by Tirunelveli District on the North and the East. The South Eastern boundary is
the Gulf of Manner. On the South and the South West, the boundaries are the Indian Ocean and the Arabian Sea.
On the West and Northwest it is bounded by Kerala. The Kanyakumari District total areas area is 1430.3Km.
The Coastal Villages elevations are 5 meter to 50 meter above mean sea level.Tirunelveli linked with the
Kanyakumari city by both road and railways. It is located south of Trichy at distance of 335km .Kanyakumari
was formed 1835 AD. It has an area of 1671.3 Km2 with 16.76 Lakh populations as per 2011 Census. The study
made by the researcher confirmed the various relief measures carried out in the affected areas in general and in
Agashteeshwaram Taluk in Kanyakumari measures be programmed in such a way that they facilities of their
livelihood besides regaining their aspirations of life.
SRGM Analyzers Tool of SDLC for Software Improving QualityIJERA Editor
Software Reliability Growth Models (SRGM) have been developed to estimate software reliability measures such as
software failure rate, number of remaining faults and software reliability. In this paper, the software analyzers tool proposed
for deriving several software reliability growth models based on Enhanced Non-homogeneous Poisson Process (ENHPP) in
the presence of imperfect debugging and error generation. The proposed models are initially formulated for the case when
there is no differentiation between failure observation and fault removal testing processes and then this extended for the case
when there is a clear differentiation between failure observation and fault removal testing processes. Many Software
Reliability Growth Models (SRGM) have been developed to describe software failures as a random process and can be used
to measure the development status during testing. With SRGM software consultants can easily measure (or evaluate) the
software reliability (or quality) and plot software reliability growth charts.
This document proposes a new framework for secure mobile commerce (m-commerce) that combines double layer encryption, steganography, and secure XML messages transferred between a mobile terminal and server. The framework is based on J2ME/MIDP and aims to provide strong security and invisibility while maintaining high operating efficiency and compatibility with many mobile terminals. It encrypts data using an elliptic curve cryptography algorithm and hides the encrypted information in images using random least significant bit steganography before transmitting between devices.
Graphical Password by Watermarking for securityIJERA Editor
The most common authentication method is to use alphanumerical usernames and passwords. This method has
been shown to have considerable disadvantage. For example, users tend to pick passwords that can be easily
guessed. On the other hand, if a password is very difficult to guess, then it is often difficult to remember. To
address this problem, some researchers have developed authentication methods that use pictures as passwords.
Graphical Password based on the fact that humans tend to remember images better. In this paper, we will
propose a new algorithm that using watermarking technique as the solution to solving image gallery attacks and
using the random character set generation for each image for resistance to shoulder surfing attack to provide
better system security. All the information images in registration phase will be process by copy right protection
of watermarking where the login page will check this information for security purposes.
A Microcontroller Based Intrusion Detection SystemIJERA Editor
A Microcontroller based Intrusion Detection System is designed and implemented. Rampant, Okintrusion to
restricted zones have highlighted the need for embedded systems that can effectively monitor, instantly alert
personnel of any breach in security and retrieve graphic evidence of any such activity in the secured area. At the
heart of the intrusion detection system is the PIC 168F77A Microcontroller that transmits pulses at 38 KHz. It is
suitably interfaced to a GSM modem that can send SMS on sight of infringement and a webcam that can take
snapshots. The report also presents the system software which has been developed in two parts: one in C++
Language using MPLAB KIT and the other written in AT COMMAND resident in the GSM modem. The
system is very cost-effective, uses easily available components and is adaptable to control systems.
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 study evaluated methods for in vitro mass propagation of Asclepias curassavica through direct and indirect regeneration. Leaf explants produced the most callus on MS medium supplemented with 2,4-D. Organogenic callus developed shoots when transferred to MS medium with BAP and GA3. Nodal explants performed better than shoot tips. Among media, L2 medium with KN and auxins produced the most shoots. L2 medium was superior for shoot multiplication and elongation compared to MS medium. This work developed an efficient protocol for micropropagation of this medicinally important plant using nodal explants on L2 medium.
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
O documento discute conceitos de colisão no Unity 3D, incluindo tipos de colisores, componentes de colisão, tratamento de colisão com scripts e ray casting. Também aborda triggers e como ignorar colisões entre objetos específicos.
El Dolmen de Dombate es un monumento megalítico funerario prehistórico situado en Galicia, España. Data de entre el Neolítico y la Edad de Bronce, hace unos 5.000 años, y consiste en una gran losa de piedra apoyada sobre otras tres, que formaban la cámara sepulcral donde se depositaban los restos humanos. Es uno de los dólmenes mejor conservados de Galicia.
El documento explica qué es el reciclaje, por qué es importante y cómo funciona el proceso de separación de residuos. El reciclaje permite reutilizar materiales después de que un artículo ha llegado al final de su vida útil, lo que reduce los costos de eliminación de basura y ahorra recursos naturales como el petróleo y los árboles. Para reciclar correctamente, los residuos se deben separar en los contenedores adecuados según su tipo, como vidrio, papel, plástico o latas.
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.
3D FLOW ANALYSIS OF AN ANNULAR DIFFUSER WITH AND WITHOUT STRUTS IAEME Publication
Numerical investigations have been carried out for an annular type gas turbine exhaust diffuser with inlet guidevanes and with and without struts. Numerical simulations were carried out to determine the pressure recovery coefficient, for a divergence angle 13o by keeping the diffusion length constant. The flow conditions at the inlet are varied to evaluate how they affect the flow development in the passage. The velocity at inlet is varied from 80 m/s to 160 m/s in the steps of 40 m/s. In the present study a (1/6)th part of the model is considered for the analysis, due to symmetry. The results for with and without struts indicates how the pressure recovery coefficient affects the efficiency of the turbine.
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.
Analysis of Heat Generation in Double Pipe Heat Exchanger: An Experimental Ev...IRJET Journal
This document summarizes research on analyzing heat generation in a double pipe heat exchanger with an elliptical fin surface contact. An experiment was conducted to compare the heat transfer rate of an elliptical fin to other fin types (tube-tube, rectangular, annular, spiral rod). The results showed the elliptical fin had a higher heat transfer rate. The document reviews several other studies analyzing different fin geometries, heat transfer optimization techniques, and computational fluid dynamics simulations of heat exchangers. It provides background on analyzing heat exchangers using methods like logarithmic mean temperature difference and effectiveness-NTU and discusses prior work optimizing dimensions, materials, and flow conditions to improve heat transfer performance.
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.
IRJET-Enhancing the Performance of Hybrid Microgrid using non Isolated Single...IRJET Journal
This document analyzes heat transfer in a light passenger car radiator with various geometrical configurations using computational fluid dynamics (CFD). It studies a staggered fin-and-tube radiator with circular and oval tubes. The radiator is modeled and analyzed in FLUENT to obtain velocity, temperature, and pressure contours. Oval tubes are found to improve heat transfer compared to circular tubes. Specifically, oval tube configurations reduce temperature differences between the tubes and air, indicating more efficient heat absorption. While circular tubes show higher temperatures, oval tube designs enhance convection and lower outlet temperatures. In conclusion, varying the tube shape geometrically through oval designs improves the radiator's thermal performance.
IRJET- Flow and Heat Transfer Charecterstics of Multiple Jet CoolingIRJET Journal
The document summarizes research on heat transfer characteristics of multiple jet cooling for electronic components. Experiments were conducted using an array of 49 water jets impinging on an electrically heated copper plate. The jet diameter was 0.5mm, arranged in a 7x7 square array with 3mm pitch. Tests were run at flow rates of 22-40 ml/min and heat fluxes of 25-200W/cm2. Results showed that heat transfer coefficient, or Nusselt number, increased with increasing heat flux and Reynolds number. Prior studies on jet impingement cooling are also summarized.
Improved Thermal Performance of Solar Air Heater Using V-Rib with Symmetrical...IJERA Editor
This document summarizes an experimental investigation of the thermal performance of a solar air heater duct with an absorber plate containing V-shaped ribs with symmetrical gaps and staggered ribs. Experiments were conducted for a Reynolds number range of 3000-14000 with various rib parameters. Results showed that the heat transfer coefficient and Nusselt number were higher for the roughened plate compared to a smooth plate, indicating enhanced heat transfer. The efficiency was also higher for the roughened plate configuration compared to the smooth plate due to the increased heat transfer. The V-rib with symmetrical gap and staggered rib geometry increased secondary flows and accelerated the air flow, improving thermal performance compared to a smooth plate.
This document summarizes a numerical investigation of flow characteristics in a C-shaped subsonic diffuser. The study validated experimental results from a C-shaped diffuser with an area ratio of 1.273 and 30 degree turn angle using computational fluid dynamics software. A series of parametric simulations were then conducted, varying the area ratio from 1.25 to 2 and turn angle from 30 to 75 degrees. The simulations found that static pressure recovery increased with higher area ratios but decreased with higher turn angles, while total pressure loss remained relatively constant with parameter changes.
3 d flow analysis of an annular diffuser with and without strutsIAEME Publication
The document summarizes a study on the 3D flow analysis of an annular diffuser with and without struts. Numerical simulations were conducted for an annular exhaust diffuser model at different inlet velocities and with or without struts. The results show that pressure recovery within the diffuser increases as flow proceeds, with pressure increasing and velocity decreasing. The presence of struts decreases the pressure recovery coefficient slightly due to increased losses, with velocity increasing along the strut portion where pressure decreases. Contour plots illustrate the velocity and pressure distributions through the diffuser.
This document summarizes a study that used finite element analysis and Monte Carlo simulation to analyze the probabilistic design and random optimization of an aerofoil wing made of composite materials. The study modeled an NACA0012 aerofoil composite structure in ANSYS and varied design parameters like chord length, ply angle, elastic modulus, and beam length randomly within defined ranges. Transient analysis was performed under varying loading conditions. Scatter plots showed maximum bending stress increased significantly with ply angle variation. Random optimization was then performed to find a set of design parameters that reduced the maximum bending stress. The best set proposed a reduced bending stress of 180.58 N/mm2 compared to 1131.79 N/mm2 from the Monte Carlo simulation
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.
This document summarizes a study that used finite element analysis and Monte Carlo simulation to analyze the probabilistic design and random optimization of an aerofoil wing made of composite materials. The study modeled an NACA0012 aerofoil composite structure in ANSYS and varied design parameters like chord length, ply angle, elastic modulus, and loading conditions randomly to analyze uncertainty in bending stress. Over 1000 simulations were run. Optimization was also performed to find a set of design variables that reduced the bending stress objective function. The best set reduced bending stress from 1131.79 N/mm2 to 180.58 N/mm2. The study concluded there was significant uncertainty when chord length and ply angle varied and provided correlations between design variables and bending
1. The document discusses an experimental study on the effect of leading edge fillet geometry on endwall film cooling effectiveness for a first-stage turbine vane. Three types of sharp slope fillets with different length-to-height ratios were tested and compared to a baseline geometry without a fillet.
2. Film cooling effectiveness distributions were obtained using pressure sensitive paint. Results showed that film cooling effectiveness increased with increasing blowing ratio. The baseline geometry provided the best film cooling near the leading edge pressure side. The effect of leading edge geometry on the suction side depended on the blowing ratio.
3. Previous literature has found that leading edge modifications can control the horseshoe vortex and secondary flows and thereby impact film cooling effectiveness
Nusselt number and friction factor correlations for solar air heater duct hav...IAEME Publication
In order to enhance the heat transfer rate of solar air heater apparatus, triangular protrusions are provided on the surface of the aluminum absorber plate to act as artificial roughness. Three kinds of absorber plates other than a smooth absorber plate with protrusions of varying apex angles are chosen for this work.
This document summarizes a study on the hydrodynamic characteristics of a swirling fluidized bed with a four duct plenum chamber. Large Geldart D-type particles (coffee beans and black pepper) were used. Numerical simulations were conducted using CFD software to validate experimental results. Key parameters like distributor pressure drop, minimum fluidization velocity, bed pressure drop, and radial/tangential velocities were analyzed experimentally and through simulations. The results show that a swirling fluidized bed can effectively fluidize large particles that are difficult to fluidize in a conventional bed. Pressure drops and velocities varied as expected with changes in air flow rates.
1. The document numerically investigates turbulent air flow in a coaxial jet burner using Reynolds Averaged Navier Stokes (RANS) modeling.
2. It compares predicted results of air axial velocity, air swirl velocity, and turbulent kinetic energy at different axial positions to experimental measurements from a previous study.
3. The simulation results show good agreement with experimental data, except at side regions where air velocity is under estimated, demonstrating RANS is a reasonably accurate approach for modeling industrial turbulent flows.
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.
Influence of number of impeller and diffuser blades on the pressure recovery ...eSAT Journals
This document summarizes a numerical analysis that investigated the influence of the number of impeller and diffuser blades on the pressure recovery of a centrifugal fan. The analysis found that higher numbers of impeller blades (up to 14 blades) resulted in better pressure recovery due to improved blade loading. Additionally, a smaller number of diffuser blades (12 blades) produced higher pressure recovery by avoiding flow separation and stall near the blades. In general, the analysis showed that configurations with more impeller blades and fewer diffuser blades achieved better static pressure recovery and lower total pressure losses across the fan.
STUDY OF HEAT TRANSFER ON BROKEN ARC ROUGHNESS ELEMENTS ON THE ABSORBER PLATE...IAEME Publication
Performance of solar air heater can be enhanced by adding roughness to the inner periphery. The present study on the effect of various shape parameters for broken arc roughness elements of heat transfer and friction factor characteristics of rectangular duct. The duct has Reynolds number (Re) range of 3000-22300, respective roughness height (e/D) values is 0.045, arc angle (α) is 60˚ and roughness width (W/w) is 5 and relatively roughness pitch is 8.
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
Introduction of Cybersecurity with OSS at Code Europe 2024Hiroshi SHIBATA
I develop the Ruby programming language, RubyGems, and Bundler, which are package managers for Ruby. Today, I will introduce how to enhance the security of your application using open-source software (OSS) examples from Ruby and RubyGems.
The first topic is CVE (Common Vulnerabilities and Exposures). I have published CVEs many times. But what exactly is a CVE? I'll provide a basic understanding of CVEs and explain how to detect and handle vulnerabilities in OSS.
Next, let's discuss package managers. Package managers play a critical role in the OSS ecosystem. I'll explain how to manage library dependencies in your application.
I'll share insights into how the Ruby and RubyGems core team works to keep our ecosystem safe. By the end of this talk, you'll have a better understanding of how to safeguard your code.
This presentation provides valuable insights into effective cost-saving techniques on AWS. Learn how to optimize your AWS resources by rightsizing, increasing elasticity, picking the right storage class, and choosing the best pricing model. Additionally, discover essential governance mechanisms to ensure continuous cost efficiency. Whether you are new to AWS or an experienced user, this presentation provides clear and practical tips to help you reduce your cloud costs and get the most out of your budget.
A Comprehensive Guide to DeFi Development Services in 2024Intelisync
DeFi represents a paradigm shift in the financial industry. Instead of relying on traditional, centralized institutions like banks, DeFi leverages blockchain technology to create a decentralized network of financial services. This means that financial transactions can occur directly between parties, without intermediaries, using smart contracts on platforms like Ethereum.
In 2024, we are witnessing an explosion of new DeFi projects and protocols, each pushing the boundaries of what’s possible in finance.
In summary, DeFi in 2024 is not just a trend; it’s a revolution that democratizes finance, enhances security and transparency, and fosters continuous innovation. As we proceed through this presentation, we'll explore the various components and services of DeFi in detail, shedding light on how they are transforming the financial landscape.
At Intelisync, we specialize in providing comprehensive DeFi development services tailored to meet the unique needs of our clients. From smart contract development to dApp creation and security audits, we ensure that your DeFi project is built with innovation, security, and scalability in mind. Trust Intelisync to guide you through the intricate landscape of decentralized finance and unlock the full potential of blockchain technology.
Ready to take your DeFi project to the next level? Partner with Intelisync for expert DeFi development services today!
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
Discover the seamless integration of RPA (Robotic Process Automation), COMPOSER, and APM with AWS IDP enhanced with Slack notifications. Explore how these technologies converge to streamline workflows, optimize performance, and ensure secure access, all while leveraging the power of AWS IDP and real-time communication via Slack notifications.
Nunit vs XUnit vs MSTest Differences Between These Unit Testing Frameworks.pdfflufftailshop
When it comes to unit testing in the .NET ecosystem, developers have a wide range of options available. Among the most popular choices are NUnit, XUnit, and MSTest. These unit testing frameworks provide essential tools and features to help ensure the quality and reliability of code. However, understanding the differences between these frameworks is crucial for selecting the most suitable one for your projects.
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.
Digital Marketing Trends in 2024 | Guide for Staying AheadWask
https://www.wask.co/ebooks/digital-marketing-trends-in-2024
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1. K. RAVI KUMAR, M.R.CH. SASTRY, K. DURGA PRASAD / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue5, September- October 2012, pp.1976-1985
Fluid Flow And Heat Transfer Analysis Of Turbulent Multiple
Circular Jets Impinging On A Flat Plate
K. DURGA PRASAD
P.G. Student
Dept. of Mechanical Engg., V.R. Siddhartha Engineering College, Vijayawada
K. RAVI KUMAR
Assistant Professor
Dept. of Mechanical Engg., V.R. Siddhartha Engineering College, Vijayawada
M.R.CH. SASTRY
Associate Professor
Dept. of Mechanical Engg., Gudlavalleru Engineering College Gudlavalleru
Abstract
Computations and Experiment technologies. Jet impingement is used as an
investigations on a Flat plate and reported with effective mechanism for achieving high localized
constant heat flux imposed on bottom surface transport rates. Single and multiple rows of jets are
and five circular jets impinges on a top surface used to achieve this objective. The most commonly
.The five circular jets consists of a central jet used geometries are axisymmetric (circular orifice
surrounded by four neighboring perimeter jets or pipe), slot (two-dimensional) nozzles, rectangular
.Lampblack flow visualization technique and (three-dimensional) and square (three-dimensional)
computation using shear stress transformation nozzles.
(K-ω) turbulent model and employed to describe The broad objectives of the paper are
the complex interaction of the wall jets and the therefore to computationally investigate (i) the flow
associated flow structure. structure of the interacting jets experimentally by oil
It is observed that the flow topology is lampblack technique, and computation. (ii) The
practical independent of Reynolds number with effect of varying h/d and Reynolds number on
in the investigation range but is significantly pressure distribution and heat transfer. .Flow
attend with the spacing between jet orifice and visualization experiments with oil-lampblack
target surface. Primary pressure peaks are technique are carried out to qualitatively corroborate
observed at the stagnation point and the the computational flow structure with visualized
secondary peaks are noticed at the interaction patterns. Similarly the computational pressure
points of wall jets. A strong correlation between distributions are compared with measured data.
nusselt number and the pressure distribution is Ashforth-Frost, S., and K. Jambunathan,
noticed. (1996) Studied the Numerical prediction of semi-
confined jet impingement and comparison with
Keywords: Jet impingement, array jet, flow experimental data., San et al.,(2001),studied the
visualization, Experiments, CFD “Optimum jet-to-jet spacing of heat transfer for
staggered arrays of impinging air jets Aldabbagh
1. Introduction and Sezai (2002)have investigated numerically the
Jet impingement flows are frequently used flow and heat transfer characteristics of impinging
in various industrial equipment for their superior laminar multiple square jets showed that more
heat and mass transfer characteristics compared to uniform heat transfer can be obtained by using
those obtained for the same amount of gas flowing shower head type impinging on the surface ,Neil et
parallel to the target surface. Impinging jets are used al.,(2005) studied about Impingement Heat transfer :
in a wide variety of applications such as cooling of Correlations and Numerical Modeling , San, J.Y.,
electronics and turbine blades, and in the heating, Tsou, Y. M., and Chen, Z. C., 2007,”Studied the
cooling, or drying of pulp, paper and textile. The Impingement heat transfer of staggered arrays of air
ability to control heat transfer from the surface by jets confined in a channel”. Bernhard et al., 2009
varying flow parameters such as jet exit velocity and reviewed the flow and heat transfer characteristics
geometrical parameters such as jet exit opening, jet- of multiple impinging jets and compared with single
to-plate spacing, and nozzle-to-nozzle spacing in impinging jets. Rajesh Kumar panda and Prasad
arrays are some of the key factors that have lead to (2011) studied the detailed flow structure and the
the sustained and widespread use of jet impingement effect of jet-to-plate spacing for round jets on the
pressure distribution and flow structure. Malladi
1976 | P a g e
2. K. RAVI KUMAR, M.R.CH. SASTRY, K. DURGA PRASAD / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue5, September- October 2012, pp.1976-1985
R.Ch. Sastry, et al., (2011), studied the fluid flow on (7) Diverging section (8) Plenum chamber (9)
a flat plate with three rectangular impinging slots Impingement chamber
jets
B 32
2. Experimental Details mm
The schematic layout of the experimental 32
set up is shown in Fig.1. Air is supplied by a mm
A A 160
Fig.2 Semi- mm
reciprocating air compressor through a calibrated
Rotameter. Flow regulating and bypass valves are
placed in supply line to control the flow rate. Air
enters into the plenum chamber through diverging 160 mm B
section to reduce the pressure fluctuations in air.
A seamless rectangular chamber of 600
mm length, 300 mm width and 6 mm thickness, is confining plate with Dimensions
used as plenum chamber, whose size is large enough The impingement plate is of five millimeter
to is 32mm. Air ejects as jet through the orifice and thick acrylic sheet of 160x160 mm is used. In order
impinges on the target surface The impingement to determine the non dimensional pressure
plate is of 160x160 mm in dimension. Chamber is a distribution on the target surface, a close array of
semi-confining plate, which contains five circular pressure tap holes of 0.8 mm diameter is drilled
orifices of dimensions 8 mm. Air ejects as jet along the plate. The tap holes are closely placed
through the orifices and impinges on the target because of the steep change of pressure expected
surface. Around the centre jet, the four perimeter due to jet interactions. Multi tube manometer is used
jets are placed 90º apart from each other. Distance for wall static pressure measurement. Impingement
between the centre jet and perimeter jets stabilize plate is placed over a stand, whose height can be
the flow and reduce the fluctuations. Air from varied by a lead screw mechanism to obtain the
plenum chamber enters into the impingement air required h/d.
chamber which is made of 160 mm width, 160 mm Flow visualization experiments are carried
height and 4mm thick mild steel square chamber. out with oil-lampblack technique. The oil and
The exit side of the impingement air chamber is a lampblack powder are mixed in proper proportion
semi-confining plate, which contains five circular lampblack powder are mixed in proper proportion
orifices of dimensions 8 mm. Air ejects as jet and painted on the target surface. The lampblack
through the orifices and impinges on the target coated target surface is kept beneath the plenum
surface. Around the centre jet, the four perimeter cylinder. The air jets, after impinging on the target
jets are placed 90º apart from each other. Distance surface, leave traces of the flow path lines on the
between the centre jet and perimeter jets is 32mm. plate. These pictures are captured by a camera.
Air ejects as jet through the orifice and impinges on
the target surface The impingement plate is of 3. Computational Methodology
160x160 mm in dimension. Figure 3 shows the geometric model that
mimics the physical model used for experiment of
8 7 6 Interest. It consists of a semi-confined plate
and160x160 mm square impingement plate. The
9 semi-confining plate consists of five circular jets of
8 mm in size. The jet ejects from the circular orifice
to impinge on the solid plate. Distance between the
1 impingement plate and the jet is varied to obtain the
5 h/d ratio from 0.5 to 4. The computational mesh
suitable for finite volume method is generated by
automatic grid generating tool GAMBIT 2.3.16.
Non-uniform grids with clustered nodes are
generated in the regions where steep gradient of
velocity is expected. Optimum grid size is selected
after the grid independence study.
For the purpose of computation, a specified
velocity inlet condition is imposed at the entry to the
3 orifice. A free stream turbulence intensity of 10% is
4 chosen at the exit of orifice. The jet after hitting the
2 plate, exits into the atmosphere in the transverse
Fig. 1 Schematic diagram of experimental set-up direction all around the plate periphery, where
(1) Test section (2) Compressor (3) Flow control constant (ambient) pressure outlet condition is
valve (4) Bypass line (5) Rotameter (6) Hoss pipe imposed. A constant heat flux value is specifies at
1977 | P a g e
3. K. RAVI KUMAR, M.R.CH. SASTRY, K. DURGA PRASAD / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue5, September- October 2012, pp.1976-1985
the bottom surface of the target plate and periphery t
is circumferentially insulated .All the input values Where Γk = µ + , Γ =µ+
are those in experiment. k
t
k
Orifice of
8mm dia k ,1 1.176 ,
2 .0 , 2
,1 Semi,confining 1.0 , , 2 1.168
plate.
Boundary conditions used for the present study are,
i) No slip boundary condition Vw = 0, at z = 0
ii) Flow inlet condition, Vx, Vy =0 ,V Z
h =Voe
Z
iii) Entrainment condition, P= Patm
The parameters investigated in the present study
include (i) effect of h/d varied as 0.5, 1, 2 and 4 (ii)
effect
of jet exit Reynolds number, varied as 9075, 10594,
Fig. 3 Schematic Diagram of the Geometry and 12106,13624.
Z
Boundary Conditions Semi confining
3.1. Mesh sensitivity
plate.
Mesh sensitivity study is carried out to ascertain the
The three dimensional flow is formulated accuracy of the numerical results. The mesh
with the following assumptions: (i) the fluid is sensitivity study is carried out by analyzing the
incompressible, (ii) the fluid properties are constant variation of static pressure distribution on the target
and (iii) the mean flow is steady. The governing plate along line A-A as shown in fig: it shows the
equations used for simulations are the Reynolds pressure distribution along A-A for different mesh
averaged continuity and momentum equations for sizes. It is clear from the table that difference in the
modeling the turbulence quantities. A finite volume value of pressure with 1.58million and 1.74 million
based solver Fluent 6.3 is used for solving the is not significant. To get advantage of computational
governing continuity, momentum and turbulence- time, mesh 1.58 million is used for this case. Similar
model equations. SIMPLE algorithm is used for mesh sensitivity study is done for all other cases.
pressure velocity coupling. The solution is Table-1
considered to be converged when the residual is in Mesh Size in Million cells Static Pressure (Pa)
the order of 10-4 for continuity, momentum,
turbulence equations and 10-8 for energy equations. 6.9 130
The κ-ω SST model is adopted for simulation. 1.52 400
Further area weighted average temperature of the 1.589 430
impingement surface is continuously monitored, so 1.745 431
that the variation will be within 1% for 1000
consecutive iterations 4. Results and Discussion
Continuity equation 4.1. Flow Structure of Impinging Jet
.(u ) 0 As each of fluid jet eject out of the orifice
Momentum equation with parabolic velocity profile a continuous
reduction in velocity taken place from its center to
. u 1
p u 0
2
the outer boundary .It is known that with increasing
distance from exit and increasing momentum
Turbulent kinetic energy(K) equation
exchange between the jet and the ambient ,the free
( k i ) k )+G – Y + S boundary of jet broadens while the potential core
= (Γk
x j
k k k contacts on the impingement surface ,the wall jets
x i x i are formed and spread radially. The wall jets
d
emanating from each impinged form a collusion
Specific dissipation rate (ω) equation ( front due to interaction with neighbors.
x Consequently an up wash flow taken place. Thus
overall structure consists of (1) potential core (2)
ui) = (Γω ) + Gω - Yω+Dω+ Sω
x j x j shear layer (3) wall jets (4) up wash flow etc. Figure
4 shows the velocity contours for the four jet-to-
plate spacing to Jet diameter ratio namely h/d = 0.5,
1, 2, 4 for Reynolds number 9075.
1978 | P a g e
4. K. RAVI KUMAR, M.R.CH. SASTRY, K. DURGA PRASAD / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue5, September- October 2012, pp.1976-1985
(a) h/d=0.5, (b) h/d=1, (c) h/d=2, (d) h/d=4
(a) This low velocity jet forms another wall jets on
the semi confining plate, shown in Fig. 4 (a &
b).But no such thing happens for higher h/d, because
(b) the second jet diffuses out by the time it reaches the
top surface, shown in Fig.4 (c &d). Fig.5 shows
velocity contours along the plane B-B. The wall jets,
thus separated from each other in the impingement
plane by the dividing stagnation line, are shown in
(c) Figs.6 and 7, by computational surface flow lines
for four h/d values of 0.5, 1, 2 and 4. The computed
and experimentally visualized flow structures
qualitatively agree well and hence confirm the
correctness of the computation. Figure 9 shows the
three dimensional separated flow. It is observed that
flow separation occurs corresponding to the
(d) separation line. Mild asymmetry is observed
however numerical values are perfectly
symmetrical. It is observed that the position of the
attachment line shifts close to the central jet as the
Fig. 4 Computed Velocity contours along plane A- h/d increase.
A, for Re = 9075
(a) h/d=0.5, (b) h/d=1, (c) h/d=2, (d) h/d=4
It can be clearly seen that in case of h/d =0.5&1 the
potential core is extended up to target surface shown
in Fig.4 (a & b). Where as in case of h/d= 2&4 the
potential core region vanishes by the time flow
reaches the target surface, shown in Fig.4(c & d).
These differences in velocity pattern happen
because of the variation in momentum exchange
between the fluid jet and ambient. The wall jets
from adjacent jets when interacts with each other a
upwash flow takes place as shown in Fig.4 when h/d
value lower (h/d =0.5 &1) the interaction prominent,
besides as the distance is less the upwash flow
fountain reaches the top wall.
(a)
(a) (b)
(b)
(c) (d)
(a) h/d=0.5, (b) h/d=1, (c) h/d=2, (d) h/d=4
Fig. 6 Computed flow structure visualized as traces
on impinging plate, for Re 9075
(c)
(d)
Fig. 5 Computed Velocity contours along B-B
plane, for Re = 9075
1979 | P a g e
5. K. RAVI KUMAR, M.R.CH. SASTRY, K. DURGA PRASAD / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue5, September- October 2012, pp.1976-1985
Fig. 7 Flow structure visualized as traces of oil lamp
black on impingement plate, for Re 9075
(a) h/d=0.5 (b) h/d=1(c) h/d=2(d) h/d=4
This may be because the flow in case of low h/d (0.5
&1) has more momentum compare to higher h/d,
hence the centre jet easily moves the surrounding
fluid
(a) (b)
(c) (d)
Fig 8 Path lines colored by velocity magnitude for Re = 9075 on plane A-A
(a) h/d=0.5, (b) h/d=1, (c) h/d=2, (d) h/d=4
4.2. Comparison of Experimental and experimental and computation along A-A
Computational Static Pressure Distribution the pressure distribution is observed on the
Figure 9 shows the comparison of non impingement surface both from experiment and
dimensional pressure distribution, between computation agreed with each other with in 3 %
1.1
Computation
Computation
Non Dimensional Pressure,P*
0.9
0.7
0.5
0.3
0.1
-0.1 -10 -5 0 5 10
Non Dimensional Axial Distance,x/d
Fig. 9 Comparison non dimensional pressure
1980 | P a g e
6. K. RAVI KUMAR, M.R.CH. SASTRY, K. DURGA PRASAD / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue5, September- October 2012, pp.1976-1985
Experimental with Computation lower h/d is more prominent hence larger peaks are
observed for lower h/d value of unity. The position
4.3. Effect of Plate Spacing to Jet Diameter Ratio of secondary peak depends upon the position of
Figure 10 shows the variation of non interaction point of wall jet and the size of the
dimensional pressure distribution with different central square. Secondary peak moves closer to
plates spacing to jet diameter ratio (h/d) for Re = center jet with increase in h/d.
9075 in line A – A peak pressure is observed at the
point of stagnation of each jet. Up wash fountain for
h/d 0.5 h/d 1 h/d 2 h/d 4
1
Non Dimensional Pressure P*
0.8
0.6
0.4
0.2
0
0 2 4 6 8
-0.2
Non Dimensional Axial Distance ,x/d
ℎ
Fig. 10 Non-dimensional Pressure distribution on line A-A for varying 𝑑
and for Re = 9075
h/d 0.5 h/d 1 h/d 2 h/d 4
1.1
Non Dimensional Pressure P*
0.9
0.7
0.5
0.3
0.1
-0.1 0 2 4 6 8
Non Dimensional Axial Distance ,x/d
Fig. 11 Non-dimensional Pressure distribution on 4.4. Variation of Nusselt Number with Non-
ℎ dimensional axial distance
line B-B for varying 𝑑 and for Re = 9075
The effect of plate spacing to jet diameter
Figure 11 shows the variation of non dimensional
ratio (h/d) for Re=9075 and q =3000 w/m2 in plane
pressure distribution in line B-B with different h/d
A-A as shown in figure. It shows that when h/d
.Here the behavior of pressure distribution in the
increases the Nusselt number at the stagnation
stagnation zone is similar to the one observed in line
region reduces for h/d=2 the maximum Nusselt
A-A. However, unlike line A-A, up wash fountain
number value in the stagnation region is lower
are prominent for high h/d hence the secondary
compared to lower (h/d=1) by absolutely 6-7%. The
peaks are observed are large for high h/d.
difference among mussel number at the center jet is
1981 | P a g e
7. K. RAVI KUMAR, M.R.CH. SASTRY, K. DURGA PRASAD / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue5, September- October 2012, pp.1976-1985
less compared to the perimeter jet, because the shear layer produced by jet nozzle exists converges
perimeter jets are more affected by low temperature towards the stagnation zone and hence the Nusselt
quiescent ambient air. If h/d is further increased the number increases at the stagnation point.
h/d 0.5 h/d 1 h/d 2 h/d 4
1
Nusselt Number, Nu
0.8
0.6
0.4
0.2
0
0 2 4 6 8
Non Dimensional Axial Distance x/d
Fig. 12 Nusselt Number distribution on line A-A;
ℎ
for varying 𝑑 , q=3000 w/m2 k and Re=9075
h/d 0.5 h/d 1 h/d 2 h/d 4
1
Nusselt Number, Nu
0.8
0.6
0.4
0.2
0
0 2 4 6 8
Non Dimensional Axial Distance ,x/d
pressure peak for higher for high Reynolds number.
Fig. 13 Nusselt Number distribution on line B-B; for At any Reynolds numbers the non dimensional
𝑯 2 pressure has the high value at the stagnation region
varying 𝑫 for Re=9075,q=3000w/m .
and reduces radially. Second peak is observed at the
second stagnation point where neighboring wall jets
4.4. Effect of Reynolds number
collide. Position of second peak is independent of
Figure 14 illustrates the dependence of non
Reynolds number.
dimensional pressure distribution on Reynolds
number for h/d = 2 on line A-A. As expected the
1982 | P a g e
8. K. RAVI KUMAR, M.R.CH. SASTRY, K. DURGA PRASAD / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue5, September- October 2012, pp.1976-1985
Re 9075 Re 10594 Re 12106 Re 13624
1
Non Dimensional Pressure,P*
0.8
0.6
0.4
0.2
0
-10 -5 0 5 10
-0.2
Non Dimensional Axial Distance ,x/d
Fig. 14 Effect of Reynolds number on non dimensional pressure distribution on line A-A
for h/d=2
Re 9075 Re 10594 Re 12106 Re 13624
1
Non Dimensional Pressure,P*
0.8
0.6
0.4
0.2
0
-8 -3 2 7
-0.2
Non Dimensional Axial Distance ,x/d
4.5. Effect of Re on Nusselt number:
Figure 16 illustrate the dependence of Nusselt
Fig. 15 Effect of Reynolds number on non number on Reynolds number for h/d=2 and q=3000
dimensional pressure distribution on line B-B for w/m2 on line A-A. As expected at any location heat
h/d=2 transfer rate is higher for high Reynolds number. As
Figure 15 shows the variation of non dimensional the flow is independent of Reynolds number, in the
pressure distribution with different Reynolds range of 9075-13624. The quantitative behavior of
number on line B-B. The secondary peak is formed Nusselt number. clearly indication that these trends
by the interaction of wall jets is higher for high are independent of Reynolds number .especially the
Reynolds number. position of secondary peak is Nusselt number is
found at the same radial location.
1983 | P a g e
9. K. RAVI KUMAR, M.R.CH. SASTRY, K. DURGA PRASAD / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue5, September- October 2012, pp.1976-1985
Re 9075 Re 10594 Re 12106 Re 13624
140
120
100
NusseltNumber Nu
80
60
40
20
0
-10 -5 0 5 10
Non Dimensional Axial Distance x/d
ℎ
Fig. 16 Nusselt Number distribution on line A-A for varying Re for 𝑑
=2 ,q =3000w/m2k
Re 9075 Re 10594 Re 12106 Re 13624
140
120
Nusselt Number Nu
100
80
60
40
20
0
-10 Non Dimensional0
-5 Axial Distance ,x/d5 10
3. The Nusselt on the surface is found to vary
Fig. 17 Nusselt Number in accordance with the flow structure. Peaks are
ℎ noticed in primary and secondary stagnation region.
distribution on line B-B; for varying Re for 𝑑 =2 ,q
2 Heat transfer is low at flow separation point. It is
=3000w/m k
observed that local heat transfer rate is higher for lower
h/d.
Conclusion 4. Heat transfer rate increases with Reynolds
1. The feature of the complex flow structure number and position of secondary peak found to be
are study using both oil lamp black technique and independent of Reynolds number.
computation .computational obtained topology of 5. The heat transfer variations are clearly co-
flow pattern on impingement surface agree well relatable not only with flow topology but also with
with the experiment. It is observed that the flow dimensionless pressure distribution.
topology is independent of the variation of Reynolds Nomenclature
number in the range 9075-13624, but it altered with d Diameter of Jet, m
variation of h/d.. h Jet-to-plate distance, m
2. The non dimensional pressure distribution P Static Pressure, Pa
obtained from experiment is similar to computation Nu Nusselt number,Nu
.This validates the usage of shear stress transport P* Non dimensional pressure
(SST) (K-ω) turbulence model for the chosen Re Reynolds number, ρvd/ µ
problem. Voe Orifice exit jet velocity, m/s
Vz Vertical velocity, m/s
1984 | P a g e
10. K. RAVI KUMAR, M.R.CH. SASTRY, K. DURGA PRASAD / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue5, September- October 2012, pp.1976-1985
Greek Symbols square jets”, International Journal of Heat
κ Turbulent kinetic energy, m²/s² and Fluid Flow, Vol.23, pp.509-518.
µ Dynamic viscosity, kg/m-s [4] Neil, Z., and Noam L., 2005,
ρ Density, kg/m³ “Impingement Heat Transfer: Correlations
Specificdissipationrate,1/sec and Numerical Modeling”,ASME Journal
ν Kinematicviscosity,m²/s of Heat Transfer ,Vol. 127,pp. 544-553.
Subscript [5] San, J.Y., Tsou, Y. M., and Chen, Z. C.,
f Fluid 2007,”Impingement heat transfer of
o Orifice exit staggered arrays of air jets confined ina
w Wall channel”, International Journal of Heat
Abbreviations and Mass Transfer, Volume 50, PP.3718-
SST Shear Stress Transport 3727.
[6] Bernhard, W., and Sebastian S., 2009,
References “Multiple Jet impingement -A Review”,
[1] Ashforth-Frost, S., and K. Jambunathan, Int. Symp. On Heat Transfer in Gas
(1996) Numerical prediction of semi- Turbine Systems, Turkey
confined jet impingement and comparison [7] Rajesh Kumar panda and
with experimental data, International B.V.S.S.S.Prasad.,2011 “Flow
Journal for Numerical methods in fluids, visualization and conjugate heat transfer
Vol.23, 295-306 study from Shower head impinging jets “
[2] San, J.Y.,and M.D.Lai,2001, “Optimum Proceeding of ASME-Turbo Expo 2011
jet –to-jet spacing of heat transfer for ,Canada.
staggered arrays of impinging air jets [8] Malladi R.Ch. Sastry, and A.V.S.S.K.S
“,International Journal of Heat and Mass Gupta., B.V.S.S.S.Prasad., 2011,”Study
Transfer,44(21),pp.3997-4007. of fluid flow on a flat plate with three
[3] Aldabbagh, L.B.Y., and Sezai, I., 2002, rectangular impinging slots jets
“Numerical simulation of three- “Proceedings of the 38th National
dimensional laminar multiple impinging Conference on Fluid Mechanics and Fluid
Power 2011”, MANIT, Bhopal.
1985 | P a g e