This document presents an experimental study on heat transfer from a flat plate placed downstream of a fence in a subsonic wind tunnel. A rectangular brass plate is heated inside the wind tunnel test section. Non-metallic fences of varying heights are placed upstream of the plate to promote turbulence. Experiments are conducted to examine the effects of fence height to plate length ratio (H/L), distance between fence and plate relative to plate length (S/L), and Reynolds number (1.5×105 ≤ ReL≤ 4.5×105). Results show the Nusselt number and friction factor strongly depend on H/L and S/L. A maximum 1.7 times enhancement in Nusselt number was
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.
Analysis of Coiled-Tube Heat Exchangers to Improve Heat Transfer Rate With Sp...IJMER
Steady heat transfer enhancement has been studied in helically coiled-tube heat exchangers. The outer side of the wall of the heat exchanger contains a helical corrugation which makes a helical rib on the inner side of the tube wall to induce additional swirling motion of fluid particles. Numerical calculations have been carried out to examine different geometrical parameters and the impact of flow and thermal boundary conditions for the heat transfer rate in laminar and transitional flow regimes. Calculated results have been compared to existing empirical formula and experimental tests to investigate the validity of the numerical results in case of common helical tube heat exchanger and additionally results of the numerical computation of corrugated straight tubes for laminar and transition flow have been validated with experimental tests available in the literature. Comparison of the flow and temperature fields in case of common helical tube and the coil with spirally corrugated wall configuration are discussed. Heat exchanger coils with helically corrugated wall configuration show 80–100% increase for the inner side heat transfer rate due to the additionally developed swirling motion while the relative pressure drop is 10–600% larger compared to the common helically coiled heat exchangers. New empirical Co-relation has been proposed for the fully developed inner side heat transfer prediction in case of helically corrugated wall configuration.
Enhancement of Heat Transfer and Thermo-Hydraulic Performance Using Triangula...IJERA Editor
Solar heat has been thrust area of research to explore renewable energy utilisation for the past few decades. In
solar air heaters artificial roughness is tried on the surface of the absorber plate by adding small roughness
elements to enhance the heat transfer rate. In the present work triangular protrusion are provided to act as
roughness elements over the surface of the aluminum absorber plate. The experimental study is carried out on
the effect of change in apex angle of protrusions on the heat transfer rate by keeping the other design parameters
unchanged. Maximum heat transfer rate and thermo-hydraulic performance between the range of apex angle 300
and 600 is studied. The Nusselt number is between 50 and 110, friction factor 4.5-6.7x10-3, Stanton number is 6-
14x10-3. The heat transfer rate and thermo-hydraulic performance are observed to be maximum for 450 apex
angle and least for the 600 plate.
Advance in micromachining technology in recent years has enabled the design and
development of miniaturized systems, which opens a promising field of applications, particularly in
the medical science and electronic-/bioengineering
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.
Analysis of Coiled-Tube Heat Exchangers to Improve Heat Transfer Rate With Sp...IJMER
Steady heat transfer enhancement has been studied in helically coiled-tube heat exchangers. The outer side of the wall of the heat exchanger contains a helical corrugation which makes a helical rib on the inner side of the tube wall to induce additional swirling motion of fluid particles. Numerical calculations have been carried out to examine different geometrical parameters and the impact of flow and thermal boundary conditions for the heat transfer rate in laminar and transitional flow regimes. Calculated results have been compared to existing empirical formula and experimental tests to investigate the validity of the numerical results in case of common helical tube heat exchanger and additionally results of the numerical computation of corrugated straight tubes for laminar and transition flow have been validated with experimental tests available in the literature. Comparison of the flow and temperature fields in case of common helical tube and the coil with spirally corrugated wall configuration are discussed. Heat exchanger coils with helically corrugated wall configuration show 80–100% increase for the inner side heat transfer rate due to the additionally developed swirling motion while the relative pressure drop is 10–600% larger compared to the common helically coiled heat exchangers. New empirical Co-relation has been proposed for the fully developed inner side heat transfer prediction in case of helically corrugated wall configuration.
Enhancement of Heat Transfer and Thermo-Hydraulic Performance Using Triangula...IJERA Editor
Solar heat has been thrust area of research to explore renewable energy utilisation for the past few decades. In
solar air heaters artificial roughness is tried on the surface of the absorber plate by adding small roughness
elements to enhance the heat transfer rate. In the present work triangular protrusion are provided to act as
roughness elements over the surface of the aluminum absorber plate. The experimental study is carried out on
the effect of change in apex angle of protrusions on the heat transfer rate by keeping the other design parameters
unchanged. Maximum heat transfer rate and thermo-hydraulic performance between the range of apex angle 300
and 600 is studied. The Nusselt number is between 50 and 110, friction factor 4.5-6.7x10-3, Stanton number is 6-
14x10-3. The heat transfer rate and thermo-hydraulic performance are observed to be maximum for 450 apex
angle and least for the 600 plate.
Advance in micromachining technology in recent years has enabled the design and
development of miniaturized systems, which opens a promising field of applications, particularly in
the medical science and electronic-/bioengineering
Heat transfer augmentation in different geometries of dimpled surface under n...eSAT Journals
Abstract The prime objective of present work is to study experimentally the heat transfer augmentation through various geometries of dimpled surfaces in longitudinal and lateral directions. In this paper horizontal rectangular plates of copper and aluminum with different dimpled geometries (like square, circular and triangular) for in-line arrangements were studied in natural convection with steady laminar external flow condition. The various parameters considered for study are Nusselt number, heat transfer coefficient and heat transfer rate for a constant Prandtl number (0.7) and Grashof number (104-107).It has been found that the heat transfer coefficient and heat transfer rate increases for various dimpled surfaces as compared to plane surface. It has been also found that the heat transfer coefficient and heat transfer rate increases along longitudinal direction as compared to lateral direction. And it is seen that heat transfer rate is maximum for triangular shape dimple when the apex of triangle is faced towards inlet of air flow Finally it is concluded that heat transfer enhancement takes place along the dimpled surface
Heat transfer augmentation in different geometries of dimpled surface under n...eSAT Publishing House
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.
Effect of artificial roughness on Thermal and Thermohydraulic efficiency in R...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
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.
EXPERIMENTAL STUDY OF HEAT TRANSFER FROM PLATE FIN ARRAY IN MIXED CONVECTION ...ijiert bestjournal
The work summarized in this paper presents an exper imental study of heat transfer from plate fin in mixed convection mode enhancement by the us e of plate fins is presented. After a brief review of the basic methods used to enhance the hea t transfer by simultaneous increase of heat transfer surface area as well as the heat tran sfer coefficient,a simple experimental method to assess the heat transfer enhancement is p resented. The method is demonstrated on plate fins as elements for the heat transfer enhanc ement,but it can in principle be applied also to other fin forms. That is varying various paramet ers (height,spacing). The order of the magnitude of heat transfer enhancement obtained exp erimentally,it was found that by a direct comparison of Nu and Re no conclusion regarding the relative performances could be made. This is because the dimensionless variables are int roduced for the scaling of heat transfer and pressure drop results from laboratory to large scal e but not for the performance comparison. Therefore a literature survey of the performance co mparison methods used in the past was also performed. Experiments will carried out on mix ed convection heat transfer from plate fin heat sinks subject to the influence of its geometry and heat flux. A total of 9 plate fins were pasted into the upper surface of the base plate. Th e area of the base plate is 150mm by 150mm. The base plate and the fins were made of alu minum. For all tested plate fin heat sinks,however,the heat transfer performance for h eat sinks with plate fins was better than that of solid pins.
CFD Analysis of Natural Convection Flow through Inclined EnclosureIJMERJOURNAL
ABSTRACT : The Natural convective laminar flow of two dimensional inclined rectangular enclosures is investigated by computational fluid dynamic analysis (fluent) in ansys.The upper and right wall keep adiabatic and other two walls are held in at different temperatures. The Rayleigh No varies from 103 to 106 to study the natural convection. The effect of inclination angle of the square and rectangle cavity on natural convection flow is studied for each combination of Rayleigh No. The effect of stream function and temperature contour show similar properties at low Rayleigh No. and it goes increases and show different pattern at high Rayleigh No
HEAT TRANSFER DURING MULTI SWIRL JET IMPINGEMENT: EXPERIMENTATIONIAEME Publication
Of the Active Cooling Techniques, Jet impingement achieves high localized heat
transfer rates. Introduction of swirl is one of the methods of augmentation of heat
transfer rates. The current work aims at verifying the expression derived in our
previous work experimentally. Three cases, for which simulations were performed
previously, are executed. The required ducts are manufactured by additive
manufacturing. Thermistors are used for measuring temperatures. Anemometer is
used to monitor air flow rates. Smoke tests are executed to demonstrate the generation
of swirl and then experimentation is executed to study the heat transfer
characteristics. The experimental results are in agreement with those of simulation
results
Numerical simulation of Pressure Drop through a Compact Helical geometryIJERA Editor
Pipes are used in every industrial thermo-fluid equipment and systems, such as tubes, ducts, heat exchangers, air conditioning and refrigerating systems etc. Flatter velocity profiles and more uniform thermal environments are extremely desirous factors for improved performance of these flow reactors and heat exchangers. One means of achieving it in laminar flow systems is to use mixers and flow inverters. In the present study a new device is introduced by changing the dean number of fluid flowing in helically coiled tubes. The objective is to study velocity profile and pressure drop in the proposed device made up from the configurations of changing radius. Pressure drop in straight, helical coil and compact helical geometry configuration were compared using computational fluid dynamics software (FLUENT) results.
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.
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.
Heat transfer augmentation in different geometries of dimpled surface under n...eSAT Journals
Abstract The prime objective of present work is to study experimentally the heat transfer augmentation through various geometries of dimpled surfaces in longitudinal and lateral directions. In this paper horizontal rectangular plates of copper and aluminum with different dimpled geometries (like square, circular and triangular) for in-line arrangements were studied in natural convection with steady laminar external flow condition. The various parameters considered for study are Nusselt number, heat transfer coefficient and heat transfer rate for a constant Prandtl number (0.7) and Grashof number (104-107).It has been found that the heat transfer coefficient and heat transfer rate increases for various dimpled surfaces as compared to plane surface. It has been also found that the heat transfer coefficient and heat transfer rate increases along longitudinal direction as compared to lateral direction. And it is seen that heat transfer rate is maximum for triangular shape dimple when the apex of triangle is faced towards inlet of air flow Finally it is concluded that heat transfer enhancement takes place along the dimpled surface
Heat transfer augmentation in different geometries of dimpled surface under n...eSAT Publishing House
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.
Effect of artificial roughness on Thermal and Thermohydraulic efficiency in R...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
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.
EXPERIMENTAL STUDY OF HEAT TRANSFER FROM PLATE FIN ARRAY IN MIXED CONVECTION ...ijiert bestjournal
The work summarized in this paper presents an exper imental study of heat transfer from plate fin in mixed convection mode enhancement by the us e of plate fins is presented. After a brief review of the basic methods used to enhance the hea t transfer by simultaneous increase of heat transfer surface area as well as the heat tran sfer coefficient,a simple experimental method to assess the heat transfer enhancement is p resented. The method is demonstrated on plate fins as elements for the heat transfer enhanc ement,but it can in principle be applied also to other fin forms. That is varying various paramet ers (height,spacing). The order of the magnitude of heat transfer enhancement obtained exp erimentally,it was found that by a direct comparison of Nu and Re no conclusion regarding the relative performances could be made. This is because the dimensionless variables are int roduced for the scaling of heat transfer and pressure drop results from laboratory to large scal e but not for the performance comparison. Therefore a literature survey of the performance co mparison methods used in the past was also performed. Experiments will carried out on mix ed convection heat transfer from plate fin heat sinks subject to the influence of its geometry and heat flux. A total of 9 plate fins were pasted into the upper surface of the base plate. Th e area of the base plate is 150mm by 150mm. The base plate and the fins were made of alu minum. For all tested plate fin heat sinks,however,the heat transfer performance for h eat sinks with plate fins was better than that of solid pins.
CFD Analysis of Natural Convection Flow through Inclined EnclosureIJMERJOURNAL
ABSTRACT : The Natural convective laminar flow of two dimensional inclined rectangular enclosures is investigated by computational fluid dynamic analysis (fluent) in ansys.The upper and right wall keep adiabatic and other two walls are held in at different temperatures. The Rayleigh No varies from 103 to 106 to study the natural convection. The effect of inclination angle of the square and rectangle cavity on natural convection flow is studied for each combination of Rayleigh No. The effect of stream function and temperature contour show similar properties at low Rayleigh No. and it goes increases and show different pattern at high Rayleigh No
HEAT TRANSFER DURING MULTI SWIRL JET IMPINGEMENT: EXPERIMENTATIONIAEME Publication
Of the Active Cooling Techniques, Jet impingement achieves high localized heat
transfer rates. Introduction of swirl is one of the methods of augmentation of heat
transfer rates. The current work aims at verifying the expression derived in our
previous work experimentally. Three cases, for which simulations were performed
previously, are executed. The required ducts are manufactured by additive
manufacturing. Thermistors are used for measuring temperatures. Anemometer is
used to monitor air flow rates. Smoke tests are executed to demonstrate the generation
of swirl and then experimentation is executed to study the heat transfer
characteristics. The experimental results are in agreement with those of simulation
results
Numerical simulation of Pressure Drop through a Compact Helical geometryIJERA Editor
Pipes are used in every industrial thermo-fluid equipment and systems, such as tubes, ducts, heat exchangers, air conditioning and refrigerating systems etc. Flatter velocity profiles and more uniform thermal environments are extremely desirous factors for improved performance of these flow reactors and heat exchangers. One means of achieving it in laminar flow systems is to use mixers and flow inverters. In the present study a new device is introduced by changing the dean number of fluid flowing in helically coiled tubes. The objective is to study velocity profile and pressure drop in the proposed device made up from the configurations of changing radius. Pressure drop in straight, helical coil and compact helical geometry configuration were compared using computational fluid dynamics software (FLUENT) results.
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.
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.
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.
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.
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.
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.
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.
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.
The Minimum Total Heating Lander By The Maximum Principle PontryaginIJERA Editor
The article will research a lander flying into the atmosphere with the flow velocity constraint, i.e. the total load
by means of minimizing the total thermal energy at the end of the landing process. The lander’s distance at the
last moment depends on the variables selected from the total thermal energy minimum. To deal with the problem
weapplyPontryagin maximum principle and scheme Dubovitskij Milutin.
Solvingboundaryusingtheparameterandthesolutionobtained inthe choiceof variables. The results of simulations
performed on Matlab.
Assessment of sanitation levels of sources of water in Osun State Capital, Ni...IJERA Editor
A study of the physicochemical and bacteriological analysis including BOD and COD was carried out for sources of water in Oshogbo the Capital of the State of Osun. Seven water sampling areas were selected to cover the low, medium and high population density areas of the State Capital. Water samples were collected from five sources of water, namely, shallow well, borehole, stream, rain and river. Water samples were collected from the well, borehole and stream water sources from Dada Estate and Isale Oshun for low density population, Ayetoro, Ogo-Oluwa and Oke-Ayepe for medium density, and Oke-Bale and Igbona for high density population areas. Three sampling points were undertaken for the rain water source while River Oshun source at Isale-Oshun was the 25th water sampling point. A total of 25 water quality parameters were analyzed for each of the 25 water sources sampled using the facility at the Rural Water And Environmental Sanitation Agency, RUWESA in Osun State Government Secretariat in Abere. Results indicated that 8 of the water quality parameters, pH, Turbidity; Magnesium hardness, Free Chlorine, Nitrite, Bacteriological, BOD and COD were not within Standards Organization of Nigeria (SON) permitted water quality standards and are of concern to sanitation of potable water in the State Capital. The level of each parameter differs from source to source as well as from level of population densities. The sources that were adjudged polluted were Ogo-Oluwa and Oke-Ayepe well sources; Ogo-Oluwa, Oke-Bale and Igbona stream sources Oke-Bale Rain source.R and the River source at Isale-Oshun. The polluted sources are all within the medium and high population density areas of the State Capital.
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.
Modelling of The Properties of Sand Mould Made of Reclaimed SandIJERA Editor
Modelling of the properties of the sand mould made of reclaimed sand bonded with sodium silicate and cured with CO2 gas is attempted in this paper. Properties considered are Mould hardness and Permeability. Regression models are developed and the correlation coefficient is determined. It is observed that the predictions of the model are matching with experimental values within +/- 5 % error.
Hydrogeological Studies At Jalakandapuram Sub – Basin Of Sarabanga Minor Basi...IJERA Editor
The main objective of the present study is to investigate the hydrogeology of the Jalakandapuram sub – basin, groundwater potential and quality of groundwater for domestic, industrial and agricultural purposes. Jalakandapuram ( Latitudes 11° 35‟30‟‟N to 11°46‟25‟‟N and Longitudes 77°48‟30‟‟ E to 78°2‟E) Sub- basin is one among the four sub- basins of the Sarabanga minor basins which comes under the Cauvery basin. It has an areal extent of about 325 Sq.Kms. The study area has been studied with aerial Photographs (Block and white) prepared under UNDP Project (1971) and satellite Imageries (IRS IA – LISS II ). The base map of the Jalakandapuram sub – basin has been prepared from the topo sheets (1: 50,000 scale) 58 E/14, 58 E/13, 58 I/2 Published by the Geological Survey of India in the year 1972. The location of the study area, its accessibility, Physiography, climate, rainfall and vegetation are presented. to classify the groundwater of Jalakandapuram sub-basin. This was done using the 25 water samples that were collected by the author and analysed in the Soil Testing Laboratory, Salem – 1. Plots of water samples in the hydrogeochemical classification diagrams (Piper‟s, Handa‟s and USSL) throw light on the quality of groundwater within the study area.
Image Detection and Count Using Open Computer Vision (Opencv)IJERA Editor
The purpose of this paper is to introduce and quickly make a reader to provide basics of OpenCV (Open Source Computer Vision) without having to go through the lengthy reference manuals and books. OpenCV is actually an open source library for image and video analysis, originally introduced more than decade ago by Intel. The latest major change took place in 2009 (OpenCV2) which includes main changes to the C++ interface. Nowadays the library has >2500 optimized algorithms. It is extensively used around the world, having >2.5M downloads and >40K people in the user group. Regardless of whether one is a novice C++ programmer or a professional software developer, unaware of OpenCV, the content should be interesting mainly for the researchers and graduate students in image processing and computer vision areas.
Maintenance cost reduction of a hydraulic excavator through oil analysisIJERA Editor
The purpose of this article is to present the economic advantages that the Oil Analysis can offer to companies
operating with hydraulic excavators. The financial advantages are the result of lower maintenance costs and
increased productivity of the equipment. Real situations of an infrastructure construction company in which there
were mechanical failures that could have been avoided if implemented with efficiency analysis of lubricants.
EFFECT OF BAFFLES GEOMETRY ON HEAT TRANSFER ENHANCEMENT INSIDE CORRUGATED DUCTIAEME Publication
The turbulent heat transfer and friction inside a corrugated square duct inserted
with various baffles geometries have been studied experimentally. Five types of baffles
(flat, rectangular, semicircular, triangular and trapezoidal) are attached on top and
bottom walls of the duct. The effects of duct wavy surface, baffle geometry, baffle
position and flow Reynolds number are examined. Air is used as the working fluid
with Reynolds number ranged from 3442.6 to 17213.19 under constant wall heat flux.
Experimental results show obtained for average Nusselt numbers and friction factor.
The results indicate that the trapezoidal baffled geometry provides a higher thermal
performance than the other type baffled one. The present work showed that the highest
thermal performance factor under the same pumping power obtained from the
experiments, is about 2.26 times more than that of plain duct. Also, it is found that the
thermal performance of the baffles attach on the bottom wall of the duct is higher than
the other baffles attach on the top
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.
Improved Thermal Performance of Solar Air Heater Using V-Rib with Symmetrical...IJERA Editor
The most efficient technique to increase the performance of solar air heater is to enhance the heat transfer by using artificial roughness in form of repeatedly used ribs on the absorbing heated absorber plate. In order to analyse the thermal performance and flow pattern of rectangular duct with aspect ratio (W/H) of 8, the present experimental investigation is performed with V-rib with Symmetrical Gap and Staggered Rib. The experiment has covered a Reynolds number (Re) range of 3000-14000, rib height 2 mm, pitch (P) 24mm, relative roughness pitch (P/e) of 12, gap width (g) 8mm, relative gap width (g/e) as 4 and angle of attack (α) 60o , number of gaps on each sides of V-rib (Ng) 3, relative roughness height (e/Dh) 0.045, staggered rib pitch (P’) 15.6mm, relative staggered rib pitch (P’/P) 0.65, staggered rib size (w) 20mm and relative staggered rib size (w/g) 2.5. Results have been compared with the smooth plate under similar flow condition to determine the enhancement in heat transfer and improvement in efficiency. Relative staggered rib pitch was kept at 0.65 and staggered rib size was kept as 2.5 times gap width.
HEAT TRANSFER AUGMENTATION OF LAMINAR NANOFLUID FLOW IN HORIZONTAL TUBE INSER...IAEME Publication
In this paper, an experimental study on the heat transfer enhancement and friction factor characteristics for fully developed laminar CuO/distilled-water (DI-water) nanofluid flow through horizontal tube inserted with different geometries of twisted tapes under constant heat flux condition ranged from 4483 to 10000 W/m^2. φ=0.08% and 0.35% volume concentrations of CuO nanoparticles are suspending in distilled water to prepare nanofluid. Twisted types made from copper material with twist ratios Y=2.6 and 5.3 twist ratios, thickness t=1 and 2mm and with semicircular and triangular cuts shape were used to study their effect on twisted tape performance. Results showed that both convective heat transfer in terms of average Nusselt number (Nu) ̅ and friction factor have significantly increasing with inserting twisted tape with nanofluids as working fluid comparing with nanofluids or DI-water in smooth tube case and this enhancement increases as both Reynold number and volume concentration increases.
The heat transfer and friction factor were
experimentally investigated in a louvered strip inserted tube in
turbulent flow region. A copper tube of (I.D=28mm, O.D=32mm)
and 900mm length was used. A louvered strip insert with
different geometrical configuration was inserted into the smooth
tube. A uniform heat flux condition was created by wrapping
heating tape of 2500 watt around the test section. Fibre glass
cloth was used as a thermal insulator which surrounds the
heating tape. Outer surface temperature of the tube were
measured at five different equally spaced points of test section by
k-typethermocouples. Two thermocouples were used to measure
the inlet and outlet temperature of water. The Reynolds numbers
were varied in the range of 2500 to 4000 with constant heat flux
of 24 kw/m2 for smooth tube and louvered strip inserted. Nusselt
number and friction factor obtained for louvered strip (with
forward backward arrangement) > Nusselt number and friction
factor for louvered strip (with semi-forward semi-backward
arrangement)> Nusselt number and friction factor for louvered
strip (with forward arrengement).
CFD Analysis of Concentric Tube Heat Exchanger Using Twisted TapesIJARIIT
In this paper, the three dimensional CFD modeling studies on heat transfer, friction factor and thermal performance
of concentric tube heat exchanger using twisted tapes (Plain, V-cut, , Jagged V-cut) with different twist ratios (y=2.0, 4.0) are
used. Twisted tapes are used to augment the heat transfer by creating turbulence in the fluid flow. Various methods are applied
to increase thermal performance of heat transfer devices such as treated surfaces, rough surfaces, swirling flow devices, coiled
tubes, and surface tension devices. Out of these twisted tape method is used to increase the thermal performance. Twisted tape
inserts on effectiveness of heat exchanger has analyzed for different Reynolds Number. The maximum thermal performance
factor was obtained by the Jagged V-cut twisted tape (H=50) insert compare to other twisted tapes. Simultaneously the friction
factor has been analyzed
Experimental Analysis Of Heat Transfer From Square Perforated Fins In Stagger...IJERA Editor
This project gives the experimental analysis of heat transfer over a flat surface equipped with Square perforated
pin fins in staggered arrangement in a rectangular channel. The Fin dimensions are 100mm in height & 25mm in
width. The range of Reynolds number is fixed & about 13,500– 42,000, the clearance ratio (C/H) 0, 0.33 and 1,
the inter-fin spacing ratio (Sy /D) 1.208, 1.524, 1.944 and 3.417. Sy i.e. stream wise distance is varies and Sx i.e.
span wise distance is constant. The friction factor, enhancement efficiency and heat transfer correlate in
equations with each other. Here we are comparing Square pin fins with cylindrical pin fins. Staggered
arrangement and perforation will enhance the heat transfer rate. Clearance ratio and inter-fin spacing ratio affect
on Enhancement efficiency. Both lower clearance ratio and lower inter-fin spacing ratio and comparatively lower
Reynolds number give higher thermal performance. Friction factor & Nusselt number are Key parameter which
relates with efficiency enhancement and heat transfer rate.
Numerical Predictions of Enhanced Impingement Jet Cooling with Ribs and Pins ...AZOJETE UNIMAID
Numerical calculations relevant to gas turbine internal wall heat transfer cooling were conducted using conjugate heat transfer (CHT) computational Fluid Dynamics (CFD) commercial codes. The CHT CFD predictions were carried out for impingement heat transfer with different types of obstacle walls (fins) on the target surfaces. A 10 × 10 row of impingement air jet holes (or hole density n of 4306 m-2) was used, which gives ten rows of holes in the cross-flow direction and only one heat transfer enhancement obstacle per impingement jet was investigated. Previously, four different shaped obstacles were investigated experimentally and were used to validate the present predictions. The obstacle walls, which were equally spaced on the centreline between each impingement jet are of the co-flow and cross-flow configurations. The impingement jet pitch X to diameter D, X/D and gap Z to diameter, Z/D ratios were kept constant at 4.66 and 3.06 for X, Z and D of 15.24, 10.00 and 3.27 mm, respectively. The obstacles investigated were ribs and rectangular pin-fins shapes, using two obstacles height H to diameter, H/D ratio of 1.38 and 2.45. Computations were carried out for three different mass flux G of 1.08, 1.48 and 1.94 kg/sm2. Relative pressure loss ∆P/P and surface average heat transfer coefficient (HTC) h predictions for the range of G, showed good agreement with the experimental results. The prediction also reveals that obstacles not only increases the turbulent flows, but also takes away most of the cooling heat transfer that produces the regions with highest thermal gradients. It also reduces the impingement gap downstream cross-flow.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Turbulent Heat Transfer from a Flat Plate Placed Downstream of a Fence
1. A. K. Darmeesh et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 10, (Part - 2) October 2015, pp.54-61
www.ijera.com 54 | P a g e
Turbulent Heat Transfer from a Flat Plate Placed Downstream of
a Fence
A. K. Darmeesh*, A. Ballil**, S. A. Abdel-Moneim***
* (Faculty of Engineering, Ajdabiya University, Libya)
** (Department of Mechanical Engineering, Benghazi University, Libya)
*** (Faculty of Engineering, Northern Boarder University, Kingdom of Saudi Arabia)
ABSTRACT
This paper presents an experimental study of the heat transfer and flow friction for turbulent flows of air over a
heated flat plate mounted downstream of a fence. A rectangular brass plate is attached to a heating unit and fixed
inside the test section of a subsonic wind tunnel. A number of non-metallic fences with different heights are used
separately to promote turbulence over the plate. A series of experiments are conducted to examine the following
parameters: fence height to plate length ratio (H/L), the distance between the fence and plate relative to plate
length (S/L) and the Reynolds number, which is calculated based on the stream wise length of the plate
(1.5×105
≤ ReL≤ 4.5×105
). The first set of the results, which is obtained for the case of the flat plate without a
fence, satisfied with other published results. The results in the cases of the plate placed downstream of a fence
revealed that the Nusselt number and friction factor are critically dependent on the fence height and the distance
between the fence and the plate. A maximum Nusselt number enhancement ratio of 1.7 was achieved
corresponding to a friction factor ratio of 2.5. New correlation was obtained for the thermal efficiency (η) based
on the Nusselt number enhancement ratio and friction factor ratio at different arrangements of the considered
parameters.
Keywords: Fence, flat plate, friction factor, heat transfer enhancement, Nusselt number, subsonic wind tunnel
I. INTRODUCTION
Heat transfer due to the passage of air over a flat
plate has been studied widely. This type of flows
occurs in many engineering and industrial
applications such as cooling of electronic
components, the flow through plate heat exchangers
and cooling of gas turbine blades. Different
techniques can be utilized to enhance and control the
heat transfer process; for example, the use of
obstacles [1], vortex generators [2], surface
roughness [3], extended surfaces [4], facing steps [5],
dimples [6], baffles [7] and fences [8]. The physical
effects of using such techniques are: to form
separated flows, to increase the disturbance and
generate vortices, which are leading to promote
turbulent flows and consequently, increasing the
efficiency of the heat transfer process. So far, various
experimental and numerical investigations have been
made to study heat transfer in turbulent flows.
Following is a summary of the key papers in this
field.
An experimental study of turbulent effects on the
heat transfer and the reattachment length downstream
of a fence under various free stream condition of air
was carried out in [9]. Another set of experimental
results of heat transfer in the turbulent boundary layer
flows was presented in [10]. The latter study showed
the influence of using surface protruding fences on
heat transfer and the behavior of the flow in the
regions behind the fence.
An active control of the turbulent flow in the
regions upstream and downstream a straight fence
was investigated experimentally in [11]. These
experiments were extended to include a swept fence
with a sweep angle of 20o
in [12]. Further
experimental investigations of the turbulent reverse
flow downstream of a fence using span-wise vortices
were carried out in [13].
Abdel-Moneim et al [14] performed a series of
experiments to investigate the flow characteristics
and the heat transfer from an electronic module fixed
on a virtual printed circuit panel, which is mounted
downstream of a straight fence. The study involved a
range of Reynolds number of 8000 to 40000. Another
experimental study for the augmentation of the heat
transfer from a heat source mounted behind a guide
fence was carried out in [15]. In the latter study the
Reynolds number ranged from 5000 to 30000.
A particle image velocimetry (PIV) was utilized
to measure velocity fields behind two-dimensional
porous fence models in a wind tunnel simulation in
[16]. The turbulence fields were analyzed using these
measurements.
Numerically, Orellano and Wengle [17]
demonstrated numerical results of turbulent flows
over a surface-mounted fence. Both the direct
numerical simulation (DNS) and the large eddy
RESEARCH ARTICLE OPEN ACCESS
2. A. K. Darmeesh et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 10, (Part - 2) October 2015, pp.54-61
www.ijera.com 55 | P a g e
simulation (LES) methods were used to solve the
Navier-Stokes equations. The obtained numerical
results were validated against experimental data.
The heat transfer and flow characteristics of
turbulent flow with one and two obstacles were
predicted numerically in [18]. The governing
equations were solved using finite difference scheme
with unstructured staggered grid. The k-ɛ turbulent
model was used with the associated wall function to
express the turbulence configuration.
A computational study of transitional separating-
reattaching flow on a square surface mounted
obstacle and a forward facing step was presented in
[19]. The results were obtained using large eddy
simulations and validated against other published
experimental and DNS data.
A numerical investigation of the heat transfer
over a plate with backward facing step with and
without fence was carried out in [20]. The geometry
and grid generation were constructed using ANSYS
ICEM software and the computations were
performed using ANSYS FLUENT software.
In the present work, the influence of fence height
and the distance between the fence and the heated
plate on the heat transfer and pressure drop are
investigated experimentally. The study also aims to
provide new correlations for the thermal performance
of heated plates mounted downstream of a fence,
within a specified range of the Reynolds number.
The manuscript is organized as follows: A brief
description of the experimental setup including
experimental procedures and data reduction is
provided in the next section. This is followed by the
experimental results, discussion and conclusions.
II. EXPERIMENTAL SETUP
The present experimental setup is designed to
investigate the heat transfer and flow characteristics
on a flat plate placed downstream of a fence for a
wide range of the Reynolds number. The experiments
are conducted in flows of air over a heated flat plate
located downstream of a fence in a subsonic wind
tunnel. The Reynolds number, based on the length of
the heating plate (L), ranged from 1.5×105
to
4.5×105
. A photograph of the general experimental
setup is displayed in Fig. (1) and a full detail of the
experimental apparatus is illustrated schematically in
Fig. (2).
Figure 1: The general experimental setup.
Figure 2: Schematic diagram of the experimental
apparatus.
The wind tunnel consists of an inlet section, test
section and a diffuser. The inlet section comprises a
fiberglass contraction, which is clamped to two slider
bars. A honey comb is attached to the inlet section for
straightening the air flow at the entrance of the
contraction cone. The diffuser section is equipped
with a fan, which is driven by a3HP electric motor
fixed at the diffuser outlet. The original test section
was replaced by a new one, which is made of steel.
The modified test section has an octagonal shape of
305 mm a side with an equivalent hydraulic diameter
of 318 mm and stream wise length of 1300 mm. The
test section contains a glass window and equipped by
a heating unit as shown in Fig (1). The heating unit
consists of a rectangular brass flat plate of 320 mm
length (L), 120 mm width (W) and 4 mm thickness,
13 thermocouples (type k), main heater, asbestos
insulation and wooden frame to prevent the heat loss
from the backside of the main heater and finally a
guard heater to create thermal equilibrium in the
asbestos insulation layer, which is placed between the
main and guard heaters.
Three different fences with different heights (H)
are used separately in each run. The fence is a
vertical plate made from a PVC sheet of 120 mm
width, 5 mm thickness and a sharp upper edge with a
backward chamfer of 45o
. A maximum fence height
of 15% of the test section height is considered and
the H/L ratios of 0.0625, 0.09375and 0.14375 are
applied. Different spacing (S) between the fence and
the leading edge of the plate, with a maximum
spacing of 7 times of the maximum fence height, are
investigated in such a manner that the ratio S/L=
0.007, 0.1875, 0.3125, 0.375, 0.45, 0.6875, 0.81 and
1. A schematic diagram of the arrangement of a fence
and the plate inside the octagonal test section is
illustrated in Fig. (3).
3. A. K. Darmeesh et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 10, (Part - 2) October 2015, pp.54-61
www.ijera.com 56 | P a g e
Figure 3: Configuration of the test section
A complete set of measuring instruments is
utilized including digital voltmeters for measuring
the voltage drop on the main and guard electric
heaters; digital multimeters for measuring the
resistance of the two heaters; two transformers for
controlling the input power to the heating plate via
supplying both the main and guard heaters by a
variable voltage and a digital thermometer with the
accuracy of ±1oC for reading thermocouples output.
The inlet air velocity is measured via a calibrated
manometer board. A standard pitot – static tube in
conjunction with an inclined manometer is used for
measuring the mean flow velocity in the hydro-
dynamically fully developed flow region. The
pressure drop of the flow at the inlet of the test
section is measured using the manometer board and
the pressure drop across the test section is measured
using inclined manometers. The inlet temperature of
the air flow is recorded by a standard thermometer.
Heat loss by conduction from the edges of the heating
plate is determined by the recording of the readings
of four thermocouples, which are embedded in the
asbestos surrounding the edges.
In each typical data run, firstly, the appropriate
fence is set upstream of the flat plate at a specific
distance between them in the test section. Secondly,
all observable joints are sealed to prevent air from
leaking. Then the air flow and the power to the
heating unit are switched on and adjusted to
predetermined values. The plate is heated over the
whole area and the input power is adjusted to
maintain the plate heat flux constant. Finally, after
about 30 minutes, when the heated plate reaches
steady state, the different variables are recorded.
These variables are: inlet air temperature, plate
surface temperature, pressure drop across the test
section, voltage and resistance of the main electric
heater. The heat transfer coefficient is determined
from the heat flux density and the difference between
the wall and fluid temperatures. The heat transfer
surface is simulated by a 0.0002 m thick metal foil
with thermocouples welded to its internal surface.
The average convective heat transfer coefficient (h) is
evaluated from
(1)
where (Ts) and (T∞) are the plate surface temperature
and the air mean film temperature respectively. ( netq
) is the heat flux, which is corrected for conduction
and radiation losses as in [21].
The average Nusselt and Reynolds numbers are
calculated based on the characteristic length of the
heating plate as follows:
and
where (ka) is the thermal conductivity of the air, (L)
is the characteristic length of the plate, (u) is the free
stream velocity and (ν) is the kinematic viscosity of
the air at the mean film temperature.
The friction factor (ƒ) is calculated in terms of
the frictional pressure drop along the test section of
the wind tunnel as follows:
(2)
where ΔP is the pressure drop across the test section,
ρ is the air density, D is the hydraulic diameter of the
test section and Lts is the length of the test section.
To evaluate the deviation inherent in the current
measurements, an uncertainty analysis is carried out.
Percentages of errors in the measurements of
electrical voltage and resistance are 0.3% and 0.2%
respectively. The uncertainty percentages of the
plate surface area, plate surface temperature and
mean film temperature measurements are 0.5%,
0.33%and 0.66% respectively. Percentages of
uncertainties in the measurements of the air flow
velocity and pressure drop are 0.5% and 2.0%
respectively. Consequently, the percentage of error of
the Nusselt number is estimated at 2%, the Reynolds
number is 1.8% and the Fanning friction factor is
5.5%.
III. RESULTS AND DISCUSSION
The current experimental setup is allowed to
investigate the heat transfer and flow characteristics
on a flat plate placed downstream of a fence for a
wide range of the Reynolds number. The obtained
results are presented and discussed in this section.
To validate the current measurements, a number
of experiments were conducted for flows over a plate
without a fence, which covered a range of the
Reynolds number from 1.3×105
to 4.45×105
. A
comparison between the present result of the average
Nusselt number and the correlations obtained in [22]
and [23] suggests that there is very good agreement
as shown in Fig. (4). The result of the friction factor
TT
q
h
s
net
ak
hL
Nu
Lu
Re
ts
2
2
1
L
D
ρu
ΔP
ƒ
4. A. K. Darmeesh et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 10, (Part - 2) October 2015, pp.54-61
www.ijera.com 57 | P a g e
is presented in Fig. (5), associated with the
correlation achieved in [22]. Good agreement is
noticed between the current result and the reference
data. The very good compatibility of the results
guarantees that the current measurements and present
experimental data are correct. Based on this the
following correlations are obtained for the average
Nusselt number and average friction factor in the
case of air flow over a heated plate without a fence:
Re0.017oNu
0.8546
L
and
.Re0.2179oƒ
-0.168
L
These correlations are valid with a small deviation of
4% for the Nusselt number and a reasonable
deviation of 8% for the friction factor, within the
considered range of the Reynolds number.
Figure 4: Validation of the current experimental
results of the average Nusselt number.
Figure 5: Validation of the current experimental
results of the friction factor.
After the positive validation procedures, further
studies were made, for the cases where a fence was
set upstream of the hot plate. As stated earlier three
different fence heights (H) at eight different spacing
(S) were investigated within the range of the
Reynolds number between 1.5×105
and 4.5×105
.
Figure (6) shows the average Nusselt number as a
function of the Reynolds number for the different
(H/L) and (S/L) configurations.
(a) S/L = 0.007
(b) S/L = 0.375
(c) S/L = 0.6875
(d) S/L = 1.00
Figure 6: Variation of the average Nusselt number as
a function of the Reynolds number of different flow
arrangements.
It is clear that the values of the Nusselt number
of the cases of flow in presence of a fence are higher
than the values in the cases of flow without a fence,
5. A. K. Darmeesh et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 10, (Part - 2) October 2015, pp.54-61
www.ijera.com 58 | P a g e
which confirm that the enhancement in the heat
transfer is achieved. It can be seen that the
enhancement in the heat transfer is significant at
relatively low ratios of (S/L). This enhancement
reduces with the increase in the spacing due to the
decay in the vortex strength. The fence configuration,
which has the highest ratio of (H/L) produces the
maximum enhancement in heat transfer among the
other configurations that are tested in this work. Also,
the enhancement in the average Nusselt number
increases with the increase in the Reynolds number
as shown in Fig. (6). The main reason for the heat
transfer enhancement owes to promote the turbulence
of the airflow via induces the recirculation flow with
secondary vortices behind the fence and the
occurrence of flow separation-reattachment
phenomena. The shear layer separates upstream of
the leading face of the fence and reattaches
downstream of the trailing face at reattachment
length depends on both Reynolds number and the
fence height. To discuss this point further, the
stream-wise flow velocity component (u) along the
mid plane of the test plate is measured at five
different test positions (x/L) starting from the
upstream edge of the plate. The velocity profiles are
then plotted for two different H/L ratios at different
S/L ratios as shown in Fig. (7). The velocity profiles
indicate that a separation-reattachment flow pattern
exists downstream of the fence. Also, the figures
reveal that the reattachment length depends on both
the free stream velocity and (H/L) ratio.
The ratio of reattachment length to the fence height
(Lr/H) is correlated in terms of the Reynolds number
and (H/L) ratio for the different fence configurations
as follows:
This correlation is valid, with a maximum
deviation of 11%, within the range of the Reynolds
number from 1.3×105
to 4.5×105
and for the range of
(H/L) from 0.0625 to 0.1437.
The average Nusselt number for the plate
downstream of a fence is correlated as a function of
Reynolds number, H/L and S/L ratios and the
following correlation is obtained:
(a1) (a2)
(b1) (b2)
(c1) (c2)
Figure 7: Velocity profiles at different positions
along the mid plane of the test plate at various S/L
ratios of 0.007 ( a1 & a2 ), 0.375 ( b1 & b2 ) and 1.0 (
c1 & c2 ).
Figure (8) shows the current results for the
Fanning friction factor in the cases of air flow in the
presence of a fence upstream of the plate. It is
obvious that the friction factor is dependent on the
Reynolds number, fence height and the distance
between the fence and the plate. However, at the high
(S/L) ratio the effect of the fence height on the
friction factor is diminished. The present data of
Fanning friction factor are correlated with the
Reynolds number, H/L and S/L as follows:
Both correlations of Nusselt number and Fanning
friction factor are valid for Reynolds number ranging
from 1.3×105
to 4.5×105
, (H/L) ratio from 0.0625 to
0.1437 and (S/L) from 0.007 to 1.0. The correlated
and the experimental data for both the average
Nusselt number and Fanning friction factor within
the investigated ranges of the different parameters are
shown in Fig. (9). Maximum deviations of ± 12% and
± 8% for the Nusselt number and friction factor
respectively.
(a) S/L = 0.007
0.00410.3926-0.2041
Lcorr S/L)(H/L)()(Re1.768ƒ 0.03570.1449
Lcorr H/L)()(Re1.0652(Lr/H)
-0.00140.15420.8156
Lcorr S/L)(H/L)()(Re0.0554Nu
6. A. K. Darmeesh et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 10, (Part - 2) October 2015, pp.54-61
www.ijera.com 59 | P a g e
(b) S/L = 0.375
(c) S/L = 0.6875
(d) S/L = 1.00
Figure 8: Variation of the Fanning friction factor as a
function of the Reynolds number of different flow
arrangements.
Finally, the thermal performance benefit of using
a fence upstream of the plate is evaluated. The
evaluation procedures are based on the condition of
the equal mass flow rate of the free air stream. First,
the ratios (Nu/Nuo) and (f/fo) at the different
investigated parameters were determined. Here the
subscript (o) in the Nusselt number and friction factor
denotes to the case of flow without a fence. In this
context, a maximum Nusselt number enhancement
ratio (Nu/Nuo) of 1.7 is achieved corresponding to a
friction factor ratio (f/fo) of 2.5. Then the thermal
efficiency ratio [η = (Nu/Nuo) / (f/fo)] was plotted
versus the Reynolds number as presented in Fig. (10).
In general, it can be seen that the thermal efficiency
ratio reduces with the increase in H/L or S/L ratios.
Additionally, the fence with H/L = 0.0625 presents
the best thermal performance; however, it provides
the lowest Nusselt number. This owes to the low flow
friction that is related to this fence arrangement.
(a) Nusselt number correlation
(b) Friction factor correlation
Figure 9: Correlations of the present experimental
data.
(a) S/L = 0.007
(b) S/L = 0.375
7. A. K. Darmeesh et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 10, (Part - 2) October 2015, pp.54-61
www.ijera.com 60 | P a g e
(c) S/L = 0.6875
(d) S/L = 1.00
Figure 10: The thermal performance under the
condition of equal mass flow rate of the air stream for
different configurations.
IV. CONCLUSIONS
Experimental investigations of the heat transfer
and flow friction for turbulent air flow over a hot
plate that is placed downstream a fence are conducted
successfully. The experiments covered a wide range
of the Reynolds number from 1.3×105
to 4.5×105
and
different geometric parameters including fence height
and the distance between the fence and the plate. The
conclusions of the study are summarized as follows:
The results of the flows without fence show very
good agreements with other published
correlations for both the Nusselt number and the
friction factor.
There is a significant enhancement in the heat
transfer associated with the increase in the
friction factor in the cases of the presence of a
fence in front of the hot plate. This enhancement
in the heat transfer increases with the increase in
the Reynolds number.
The highest H/L ratio used in this work provides
the largest heat transfer enhancement. The
enhancement in heat transfer decreases as the
distance between the fence and plate increases,
in general.
New correlations for the Nusselt number and
friction factor are obtained, which is valid within
the investigated range of the considered
parameters.
A maximum enhancement in the average Nusselt
number of 70% is achieved at the condition
(Re=1.3×105
, H/L = 0.1437 and S/L = 0.375).
Whereas, this thermal enhancement is associated
with an increase in the friction factor by 150%.
Based on the equal mass flow rate condition, the
fence with H/L = 0.0625 produces the best
thermal performance.
REFERENCES
[1] A. Korichi and L. Oufer, Heat transfer
enhancement in oscillatory flow in channel
with periodically upper and lower walls
mounted obstacles, International Journal of
Heat and Fluid Flow, 28(5), 2007, 1003-
1012.
[2] M. C. Gentry and A. M. Jacobi, Heat
transfer enhancement by delta-wing vortex
generators on a flat plate: Vortex
interactions with the boundary layer,
Experimental Thermal and Fluid Science,
14(3), 1997, 231-241.
[3] R. R. Yenare and K. V. Mali, Experimental
study for Heat transfer enhancement due to
surface roughness at laminar flow,
International Journal of Engineering
Research and Applications, 4(3), 2014, 239-
243.
[4] A. Diani, S. Mancin, C. Zilio and L.
Rossetto, An assessment on air forced
convection on extended surfaces:
Experimental results and numerical
modeling, International Journal of Thermal
Sciences,67, 2013, 120-134
[5] A. S. Kherbeet, H. A. Mohammed, K. M.
Munisamy and B. H. Salman, The effect of
step height of microscale backward-facing
step on mixed convection nanofluid flow
and heat transfer characteristics,
International Journal of Heat and Mass
Transfer, 68, 2014, 554-556.
[6] D. R. Giram and A. M. Patil, Experimental
and theoretical analysis of heat transfer
augmentation from dimpled surface,
International Journal of Engineering
Research and Applications, 3(5), 2013, 19-
23.
[7] R. Karwa, B. K. Maheshwari and N. Karwa,
Experimental study of heat transfer
enhancement in an asymmetrically heated
rectangular duct with perforated baffles,
International Communications in Heat and
Mass Transfer, 32(1-2), 2005, 275-284.
[8] J. J. Hwang, T. Y. Lia and T. M. Liou,
Effect of fence thickness on pressure drop
and heat transfer in a perforated-fenced
channel, International Journal of Heat and
Mass Transfer, 41(4-5), 1998, 811-816.
8. A. K. Darmeesh et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 10, (Part - 2) October 2015, pp.54-61
www.ijera.com 61 | P a g e
[9] A. Žukauskas and A. Pedišius, Free-stream
turbulence effects on the heat transfer
through the turbulent boundary layer behind
a fence, International Communications in
Heat and Mass Transfer, 10(4), 1983, 277-
286.
[10] A. Žukauskas and A. Pedišius, Heat transfer
to reattached fluid flow downstream of a
fence, Wärme - und Stoffübertragung, 21(2-
3), 1987, 125-131.
[11] H. A. Siller and H. H. Fernholz, Control of
the separated flow downstream of a two-
dimensional fence by low-frequency
forcing, Applied Scientific Research, 57(3-
4), 1997, 309-318.
[12] A. Huppertz and H. H. Fernholz, Active
control of the turbulent flow over a swept
fence, European Journal of Mechanics -
B/Fluids, 21(4), 2002, 429-446.
[13] H. A. Siller and H.-H. Fernholz,
Manipulation of the reverse-flow region
downstream of a fence by spanwise vortices,
European Journal of Mechanics- B/Fluids,
26(2), 2007, 236-257.
[14] S. A. Abdel-Moneim, A. R. Elshamy, E. F.
Atwan and A. M. Esmaeel, Heat transfer
from an electronic module placed
downstream of a fence, Proceedings of the
10th Int. Conf. On Aerospace Sciences &
Aviation Technology (ASAT10), Cairo,
Egypt, 2003, Vol. I, Paper No.TH-1.
[15] R. K. Ali, Augmentation of heat transfer
from heat source placed downstream a guide
fence: An experimental study, Experimental
Thermal and Fluid Science, 33(4), 2009,
728-734.
[16] Z. Dong, W. Luo, G. Qian, P. Lu and H.
Wang, A wind tunnel simulation of the
turbulence fields behind upright porous
wind fences, Journal of Arid Environments,
74(2), 2010, 193-207.
[17] A. Orellano and H. Wengle, Numerical
simulation (DNS and LES) of manipulated
turbulent boundary layer flow over a
surface-mounted fence, European Journal of
Mechanics- B/Fluids, 19(5), 2000, 765-788.
[18] Y-T. Yang and S. Yang, Numerical study of
turbulent flow in two-dimensional channel
with surface mounted obstacle, International
Journal of Heat and Mass Transfer, 37(18),
1994, 2985-2991.
[19] I. E. Abdalla, Z. Yang and M. Cook,
Computational analysis and flow structure
of a transitional separated-reattached flow
over a surface mounted obstacle and a
forward-facing step, International Journal
of Computational Fluid Dynamics, 23
(1), 2009, 25-57.
[20] H. Togun, T. Abdulrazzaq, S. N. Kazi, A.
Badarudin, M. K. A. Ariffin and M. N. M.
Zubir, Numerical Study of Heat Transfer
and Laminar Flow over a Backward Facing
Step with and without Obstacle,
International Journal of Mechanical,
Aerospace, Industrial and Mechatronics
Engineering, 8(2), 2014, 361-365.
[21] S. A. Abdel-Moneim, E. F. Atwan and A.
R. Alchemy, Heat transfer and flow friction
in a rectangular duct with repeated multiple
V-ribs mounted on the bottom wall,
Proceedings of the 12th Int. Mechanical
Power Engineering Conference (IMPEC12),
Mansora, Egypt, 2001, Vol. 2, pp. H11-H25.
[22] F. P. Incropera and D. P. Dewitt,
Introduction to Heat Transfer (John Wiley
& Sons, 2002).
[23] W. M. Kays and M. E. Crawford,
Convective Heat and Mass Transfer
(McGraw-Hill, New York, 1980).