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
Heat transfer enhancement and friction factor analysis in tube using conical ...eSAT Journals
Abstract Role of the conical spring array for the heat transfer enhancement and pressure drop change in a pipe with constant heat flux boundary condition was investigated. Three different arrangements of conical spring array inserts were used in the experimental setup. Conical spring inserts with diverging conical spring, converging-diverging conical spring and converging conical spring array inserts arrangements were used. Water was used as a working fluid in the experimental setup. It was found that use of conical spring array inserts arrangement leads to enhancement in heat transfer. Higher heat transfer rate was achieved in the divergent spring array arrangement than the converging-diverging and converging arrangement. However, maximum friction factor is achieved in the diverging spring array insert arrangement. By increasing the Reynolds Number for different turbulator arrangement, the significant increase in Nusselt number was obtained. The enhancement in Nusselt Number for the diverging, converging-diverging, converging conical spring array arrangement was 645% ,431% and 259% respectively. The heat transfer enhancement efficiency can be evaluated based on the power consumption per unit mass of fluid. Heat transfer enhancement efficiencies were found for the divergent spring array arrangement up to 277% and for the convergent-divergent spring arrangement up to 212% and for the convergent spring array arrangement up to 153%. Keywords— Heat exchanger, Heat transfer enhancement, Friction factor, Conical spring turbulator, Heat transfer enhancement efficiency
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.
Experimental Investigation of Heat Transfer Enhancement by Using Clockwise an...ijiert bestjournal
Present Experimental work shows result obtain from experimentation of heat transfer enhancement in
circular horizontal tube by using clockwise and counterclockwise corrugated twisted tape inserts with
working fluid is air. Experiments conducted on plain circular tube with or without c-cc corrugated
twisted tube. During experiment constant heat flux and different mass flow rate condition. The c-cc
corrugated twisted tape are of same pitch and twist ratio but three different angle of rotation in
clockwise and counter clockwise direction as 30˚, 60˚, 90˚ respectively. The Reynolds no. varied from
4000 to 10000. Heat transfer coefficient and pressure drop are calculated and results are compared with
the plain tube without inserts. Finally heat transfer enhances with clockwise and counterclockwise
corrugated twisted tape inserts as compared to plain tube varied from 8 % to 44 % for various inserts.
Plain twisted tape results are also compared with the same results.
Experimental investigation of double pipe heat exchanger with helical fins on...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 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
Heat transfer enhancement and friction factor analysis in tube using conical ...eSAT Journals
Abstract Role of the conical spring array for the heat transfer enhancement and pressure drop change in a pipe with constant heat flux boundary condition was investigated. Three different arrangements of conical spring array inserts were used in the experimental setup. Conical spring inserts with diverging conical spring, converging-diverging conical spring and converging conical spring array inserts arrangements were used. Water was used as a working fluid in the experimental setup. It was found that use of conical spring array inserts arrangement leads to enhancement in heat transfer. Higher heat transfer rate was achieved in the divergent spring array arrangement than the converging-diverging and converging arrangement. However, maximum friction factor is achieved in the diverging spring array insert arrangement. By increasing the Reynolds Number for different turbulator arrangement, the significant increase in Nusselt number was obtained. The enhancement in Nusselt Number for the diverging, converging-diverging, converging conical spring array arrangement was 645% ,431% and 259% respectively. The heat transfer enhancement efficiency can be evaluated based on the power consumption per unit mass of fluid. Heat transfer enhancement efficiencies were found for the divergent spring array arrangement up to 277% and for the convergent-divergent spring arrangement up to 212% and for the convergent spring array arrangement up to 153%. Keywords— Heat exchanger, Heat transfer enhancement, Friction factor, Conical spring turbulator, Heat transfer enhancement efficiency
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.
Experimental Investigation of Heat Transfer Enhancement by Using Clockwise an...ijiert bestjournal
Present Experimental work shows result obtain from experimentation of heat transfer enhancement in
circular horizontal tube by using clockwise and counterclockwise corrugated twisted tape inserts with
working fluid is air. Experiments conducted on plain circular tube with or without c-cc corrugated
twisted tube. During experiment constant heat flux and different mass flow rate condition. The c-cc
corrugated twisted tape are of same pitch and twist ratio but three different angle of rotation in
clockwise and counter clockwise direction as 30˚, 60˚, 90˚ respectively. The Reynolds no. varied from
4000 to 10000. Heat transfer coefficient and pressure drop are calculated and results are compared with
the plain tube without inserts. Finally heat transfer enhances with clockwise and counterclockwise
corrugated twisted tape inserts as compared to plain tube varied from 8 % to 44 % for various inserts.
Plain twisted tape results are also compared with the same results.
Experimental investigation of double pipe heat exchanger with helical fins on...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
Experimental Study of Heat Transfer Enhancement of Pipe-inPipe Helical Coil H...iosrjce
Heat transfer enhancement in pipe in pipe helical coils has been research by many researchers.
While the many literatures available on heat transfer characteristics of helical coil heat exchangers. There is
very few published on validate experimental results through Computational Fluid Dynamics. This paper focuses
on experimental investigation of fluid-to-fluid heat transfer enhancement of pipe-in-pipe helical coil tubes. The
methodology of experimental analysis of a helical tubes heat exchanger, the effect of the inside tubes at constant
value of mass flow rate in Dean Number and also established the surface heat transfer coefficient. Heat transfer
characteristics inside pipe-in-pipe helical coils for various boundary conditions, that the specification of a
constant temperature at hot water inlet, constant mass flow rate. Hence, the pipe-in-pipe heat exchanger is
considering different mass flow rate inside and annulus. The fabrication of experimental setup is estimate the
heat transfer enhancement in inside helical coil tubes
Experimental Investigation of a Helical Coil Heat Exchangerinventy
Helical coil heat exchangers are one of the most common equipment found in many industrial applications. Helical coil heat exchanger is one of the devices which are used for the recovery system. The helical coil heat exchangers can be made in the form of a shell and tube heat exchangers and can be used for industrial applications such as power generation, nuclear industry, process plants, heat recovery systems, refrigeration, food industry etc. In our work we had designed, fabricated and experimentally analysed a helical coil heat exchanger and a straight tube heat exchanger. From the observations and calculations, the results of the helical coil heat exchanger and straight tube heat exchanger are obtained and are compared. From our obtained results, the helical coil heat exchanger showed increase in the heat transfer rate, effectiveness and overall heat transfer coefficient over the straight tube heat exchanger on all mass flow rates and operating conditions. The centrifugal force due to the curvature of the tube results in the secondary flow development which enhances the heat transfer rate. Comparative study shows that helical coil heat exchanger is having better performance that straight tube heat exchanger.
Heat exchangers are used widely in industrial application such as chemical,
food processing, power production, refrigeration and air-conditioning
industries. Helical coiled heat exchangers are used in order to obtain a large
heat transfer per unit volume and to enhance the heat transfer rate on the inside
surface. In the present study, CFD simulations are carried out for a counter
flow tube in tube helical heat exchanger where hot water flows through the
inner tube and cold water flows through the outer tube. From the simulation
results heat transfer coefficient, pressure drop and nusselt number are
calculated. The heat transfer characteristics of the same are compared with that
of a counter flow tube in tube straight tube heat exchanger of same length
under same temperature and flow conditions. CFD simulation results showed
that the helical tube in tube heat exchanger is more effective than the straight
tube in tube heat exchanger.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Helically Coiled Tube with Different Geometry and Curvature Ratio on Convecti...AM Publications
A helically coil-tube heat exchanger is generally applied in industry applications due to its compact structure, larger heat transfer area and higher heat transfer capability. Several studies from literature have also indicated that heat transfer rate in helically coiled tube are superior to straight tube due to complex flow pattern exist inside helical pipe. The concept behind compact heat exchanger is to decrease size and increase heat load which is the typical feature of modern helical tube heat exchanger. While the heat transfer characteristics of helical coil heat exchangers are available in the literature, This paper elaborates a brief review on different curvature ratio and geometry of tubes in heat transfer through heat exchangers.
Numerical Analysis of Heat Transfer Enhancement in Pipe-inPipe Helical Coiled...iosrjce
These paper focuses on the effect of the inside tubes at constant value of mass flow rate and variation
of annulus mass flow rate on effect of Dean Number and overall heat transfer coefficient with constant wall
temperature, CFD analysis of a helically coiled heat exchanger. Also deals with the effect of Dean Number with
respect to Reynolds Number and Nusselt Number and Overall Heat Transfer coefficient on change of coil
configuration of helically coiled tube. The particular difference in this study in comparison with the other
similar studies was the boundary conditions for the helical coils. The results indicate that with the decrease the
inner coil diameter, the overall heat transfer coefficient is increased
Experimental Investigation on Heat Transfer Enhancement in Laminar Flow in Ci...IDES Editor
An experimental investigation of heat transfer and
friction factor of a smooth tube fitted with full length twisted
tape inserts for laminar flow have been studied under uniform
wall heat flux condition. The experiments has been carried
out to study the tape fin effect by using full length tape inserts
of different materials namely Aluminum, Stainless steel and
insulated tape. The tapes have twist ratios from 5.2 to 3.4. It is
found that, for the flow in smooth tubes, full length twisted
tapes yield improvement in average Nusselt number, for
Reynolds number range of 200 to 2000.For Aluminum tapes,
the maximum improvement in Nusselt number range from
50% to 100%; for Stainless steel tapes, maximum
improvement in Nusselt number range from 40% to 94% and
for insulated tapes, maximum improvement in Nusselt
number range from 40% to 67%. The isothermal friction factor
for the flow with the twisted tape inserts are 340% to 750 %
higher as compared with those of smooth tube flow, in the
given range of twist ratios.
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
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).
The turbo machine is an energy conversion device which converts mechanical energy to kinetic/pressure energy or vice versa. The conversion is done through the dynamic interaction between a continuously flowing fluid and rotating machine component. Turbo machines comprise various types of fans, blowers, compressors, pumps, turbines etc. More and more experimental research work is available in the field of turbo machine design and its evaluation. Literature review has revealed that a few literatures are available on three dimensional numerical analysis of a centrifugal fan/blower. Literature review in present work is highly focused on centrifugal blower and use of CFD techniques in turbo machines. In this course of work, input parameters and design parameters of centrifugal blower is obtained as per church and Osborne design methodology developed by Kinnari Shah, PROF. NitinVibhakar. Fluid model is made as per this design data in PRO-E SOFTWARE. And this fluid model is simulated using computational fluid dynamics (CFD) approach in ANSYS (CFX). Numerical analysis carried out in this work is to understand the flow characteristics at design and off-design conditions under varying mass flow rates, varying rotational speeds and number of blades in both design methodology. This numerical analysis is under consideration of steady flow and for rotational domain (frozen rotor interference) is used. Performance curves are obtained under different variable inlet parameters like volume flow rate, rotational speed and number of impeller blades. Here mass flow rate as a inlet boundary condition and static pressure as a outlet boundary condition. Volume flow rate is changed by changing the mass flow rate at inlet. Overall work carried out on flow behaviour and performance graphs for different cases are discussed in length in results and discussions chapter. Comparative evaluation of two design method indicates that error in static pressure gradient is higher in Osborne design rather than church design, and performance parameters are better for church design than the Osborne design.
A Review on Comparison between Shell And Tube Heat Exchanger And Helical Coil...ijiert bestjournal
The curved shape of the tube causes the flowing fluid to experience centrifugal force. The
extent of centrifugal force experienced depends on the local axial velocity of the fluid particle
and radius of curvature of the coil. The fluid particles flowing at the core of the pipe have
higher velocities than those flowing near to the pipe wall. Thus the fluid particles flowing
close to the tube wall experience a lower centrifugal force than the fluid particles flowing in
the tube core. This causes the fluid from the core region to be pushed towards the outer wall.
This stream bifurcates at the wall and drives the fluid towards the inner wall along the tube
periphery, causing generation of counter-rotating vortices called secondary flows which
produce additional transport of the fluid over the cross section of the pipe. This additional
convective transport increases heat transfer and the pressure drop when compared to that in a
straight tube.
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.
Experimental Study of Heat Transfer Enhancement of Pipe-inPipe Helical Coil H...iosrjce
Heat transfer enhancement in pipe in pipe helical coils has been research by many researchers.
While the many literatures available on heat transfer characteristics of helical coil heat exchangers. There is
very few published on validate experimental results through Computational Fluid Dynamics. This paper focuses
on experimental investigation of fluid-to-fluid heat transfer enhancement of pipe-in-pipe helical coil tubes. The
methodology of experimental analysis of a helical tubes heat exchanger, the effect of the inside tubes at constant
value of mass flow rate in Dean Number and also established the surface heat transfer coefficient. Heat transfer
characteristics inside pipe-in-pipe helical coils for various boundary conditions, that the specification of a
constant temperature at hot water inlet, constant mass flow rate. Hence, the pipe-in-pipe heat exchanger is
considering different mass flow rate inside and annulus. The fabrication of experimental setup is estimate the
heat transfer enhancement in inside helical coil tubes
Experimental Investigation of a Helical Coil Heat Exchangerinventy
Helical coil heat exchangers are one of the most common equipment found in many industrial applications. Helical coil heat exchanger is one of the devices which are used for the recovery system. The helical coil heat exchangers can be made in the form of a shell and tube heat exchangers and can be used for industrial applications such as power generation, nuclear industry, process plants, heat recovery systems, refrigeration, food industry etc. In our work we had designed, fabricated and experimentally analysed a helical coil heat exchanger and a straight tube heat exchanger. From the observations and calculations, the results of the helical coil heat exchanger and straight tube heat exchanger are obtained and are compared. From our obtained results, the helical coil heat exchanger showed increase in the heat transfer rate, effectiveness and overall heat transfer coefficient over the straight tube heat exchanger on all mass flow rates and operating conditions. The centrifugal force due to the curvature of the tube results in the secondary flow development which enhances the heat transfer rate. Comparative study shows that helical coil heat exchanger is having better performance that straight tube heat exchanger.
Heat exchangers are used widely in industrial application such as chemical,
food processing, power production, refrigeration and air-conditioning
industries. Helical coiled heat exchangers are used in order to obtain a large
heat transfer per unit volume and to enhance the heat transfer rate on the inside
surface. In the present study, CFD simulations are carried out for a counter
flow tube in tube helical heat exchanger where hot water flows through the
inner tube and cold water flows through the outer tube. From the simulation
results heat transfer coefficient, pressure drop and nusselt number are
calculated. The heat transfer characteristics of the same are compared with that
of a counter flow tube in tube straight tube heat exchanger of same length
under same temperature and flow conditions. CFD simulation results showed
that the helical tube in tube heat exchanger is more effective than the straight
tube in tube heat exchanger.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Helically Coiled Tube with Different Geometry and Curvature Ratio on Convecti...AM Publications
A helically coil-tube heat exchanger is generally applied in industry applications due to its compact structure, larger heat transfer area and higher heat transfer capability. Several studies from literature have also indicated that heat transfer rate in helically coiled tube are superior to straight tube due to complex flow pattern exist inside helical pipe. The concept behind compact heat exchanger is to decrease size and increase heat load which is the typical feature of modern helical tube heat exchanger. While the heat transfer characteristics of helical coil heat exchangers are available in the literature, This paper elaborates a brief review on different curvature ratio and geometry of tubes in heat transfer through heat exchangers.
Numerical Analysis of Heat Transfer Enhancement in Pipe-inPipe Helical Coiled...iosrjce
These paper focuses on the effect of the inside tubes at constant value of mass flow rate and variation
of annulus mass flow rate on effect of Dean Number and overall heat transfer coefficient with constant wall
temperature, CFD analysis of a helically coiled heat exchanger. Also deals with the effect of Dean Number with
respect to Reynolds Number and Nusselt Number and Overall Heat Transfer coefficient on change of coil
configuration of helically coiled tube. The particular difference in this study in comparison with the other
similar studies was the boundary conditions for the helical coils. The results indicate that with the decrease the
inner coil diameter, the overall heat transfer coefficient is increased
Experimental Investigation on Heat Transfer Enhancement in Laminar Flow in Ci...IDES Editor
An experimental investigation of heat transfer and
friction factor of a smooth tube fitted with full length twisted
tape inserts for laminar flow have been studied under uniform
wall heat flux condition. The experiments has been carried
out to study the tape fin effect by using full length tape inserts
of different materials namely Aluminum, Stainless steel and
insulated tape. The tapes have twist ratios from 5.2 to 3.4. It is
found that, for the flow in smooth tubes, full length twisted
tapes yield improvement in average Nusselt number, for
Reynolds number range of 200 to 2000.For Aluminum tapes,
the maximum improvement in Nusselt number range from
50% to 100%; for Stainless steel tapes, maximum
improvement in Nusselt number range from 40% to 94% and
for insulated tapes, maximum improvement in Nusselt
number range from 40% to 67%. The isothermal friction factor
for the flow with the twisted tape inserts are 340% to 750 %
higher as compared with those of smooth tube flow, in the
given range of twist ratios.
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
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).
The turbo machine is an energy conversion device which converts mechanical energy to kinetic/pressure energy or vice versa. The conversion is done through the dynamic interaction between a continuously flowing fluid and rotating machine component. Turbo machines comprise various types of fans, blowers, compressors, pumps, turbines etc. More and more experimental research work is available in the field of turbo machine design and its evaluation. Literature review has revealed that a few literatures are available on three dimensional numerical analysis of a centrifugal fan/blower. Literature review in present work is highly focused on centrifugal blower and use of CFD techniques in turbo machines. In this course of work, input parameters and design parameters of centrifugal blower is obtained as per church and Osborne design methodology developed by Kinnari Shah, PROF. NitinVibhakar. Fluid model is made as per this design data in PRO-E SOFTWARE. And this fluid model is simulated using computational fluid dynamics (CFD) approach in ANSYS (CFX). Numerical analysis carried out in this work is to understand the flow characteristics at design and off-design conditions under varying mass flow rates, varying rotational speeds and number of blades in both design methodology. This numerical analysis is under consideration of steady flow and for rotational domain (frozen rotor interference) is used. Performance curves are obtained under different variable inlet parameters like volume flow rate, rotational speed and number of impeller blades. Here mass flow rate as a inlet boundary condition and static pressure as a outlet boundary condition. Volume flow rate is changed by changing the mass flow rate at inlet. Overall work carried out on flow behaviour and performance graphs for different cases are discussed in length in results and discussions chapter. Comparative evaluation of two design method indicates that error in static pressure gradient is higher in Osborne design rather than church design, and performance parameters are better for church design than the Osborne design.
A Review on Comparison between Shell And Tube Heat Exchanger And Helical Coil...ijiert bestjournal
The curved shape of the tube causes the flowing fluid to experience centrifugal force. The
extent of centrifugal force experienced depends on the local axial velocity of the fluid particle
and radius of curvature of the coil. The fluid particles flowing at the core of the pipe have
higher velocities than those flowing near to the pipe wall. Thus the fluid particles flowing
close to the tube wall experience a lower centrifugal force than the fluid particles flowing in
the tube core. This causes the fluid from the core region to be pushed towards the outer wall.
This stream bifurcates at the wall and drives the fluid towards the inner wall along the tube
periphery, causing generation of counter-rotating vortices called secondary flows which
produce additional transport of the fluid over the cross section of the pipe. This additional
convective transport increases heat transfer and the pressure drop when compared to that in a
straight tube.
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.
Evaluation of Convective Heat Transfer Coefficient of Air Flowing Through an ...Bishal Bhandari
The heat transfer coefficient is the most influential parameter in designing of the ducts. The heat transfer coefficient varies with varying velocity, inclination and heat input. The nature of the graph of the convective heat transfer coefficient for a different velocity of air and at a different inclination of the circular Duct was plotted and the result was discussed.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Thermal analysis of various duct cross sections using altair hyperworks softwaresushil Choudhary
In this work thermal analysis and comparison of various duct cross sections is done computationally using Altair
Hyperworks Software. Simple Analytical results were obtained for conduction and convection through the ducts
which can be used to build up thermal circuit. The inner surface of all ducts is maintained at constant
temperature and ambient air is at certain temperature that is less than inner surface temperature of pipe. Due to
temperature difference heat will flow from higher temperature to lower temperature. Due to temperature
difference heat will flow from higher temperature to lower temperature. The material of pipe provides
conductive resistance and air provides convective resistance. Hence this is a mix mode of heat transfer. The heat
transfer takes place in one dimension only and properties are considered to be isotropic. The ducts are assumed
to be made of aluminium having known thermal conductivity and density. The surroundings of ducts have
known convective heat transfer coefficient and temperature. The results are obtained on hyperview which are for
heat flux, temperature gradient and grid temperature. The different characteristics can be obtained by varying the
material of the ducts.
Turbulent Heat Transfer from a Flat Plate Placed Downstream of a FenceIJERA Editor
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.
An experimental study of heat transfer in plane circular tube fitted with the V-Shaped Aluminum
turbulators is performed for plane circular tube. The objective of this Project work is to analyses heat transfer
coefficient and friction characteristics in a plane circular tube fitted with the V-Shaped Aluminum turbulators.
The experimentations are firstly carried out on the plane circular pipe and heat transfer augmentation were
recorded and then the v-shaped Aluminum turbulators are fitted in the same plane pipe and then again the heat
transfer augmentation is recorded and then both of them is compared. Experimental investigations have been
carried out to study the effects of the V-Shaped Aluminum turbulators on heat transfer, friction and
enhancement efficiency, in a circular tube. We used the V-Shaped aluminum turbulators with the turbulator
element length of 200mm, 160mm and 120mm.We found the heat transfer argumentation.The mean heat
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Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
1. International Journal of Engineering and Technical Research (IJETR)
ISSN: 2321-0869 (O) 2454-4698 (P), Volume-5, Issue-4, August 2016
61 www.erpublication.org
Abstract—The influence of delta wing vortex generators on
the wall of rectangular duct has been investigated in this study.
The angle of attack of vortex generators systematically varied in
this study to determine it’s effect on the heat transfer within the
rectangular duct of hydraulic diameter. The effect of delta wing
vortex generators at different angle of attack on pressure drop,
heat transfer coefficient, friction factor, Nusselt number are
reported for the Reynolds number based on the duct hydraulic
diameter in the range of 8000-20000. The experimental results
obtained with vortex generator is placed in comparison with the
experimental results obtained by without vortex generator to
define heat transfer enhancement factor in a duct. The
experimental results of the present study for friction factor and
Nusselt number in smooth rectangular duct agree well with
values estimated from correlations proposed by Blasius and
Dittus-Boelter respectively.
Index Terms—Heat transfer, Pressure drop, Delta wing type
of vortex generator, Nusselt number, Friction factor.
I. INTRODUCTION
In many of industrial engineering applications several
convective heat transfer methods are employed to improve the
thermal performance of heat transfer devices such as treated
surface, rough surface as well as incorporation of inserts like
vortex generators, turbulence promoters etc. Therefore the
heat transfer applications considering internal flow and mixed
convection in a non-circular ducts and channels have been
studied by many of researchers. For many of industrial
applications it becomes more essential to improve the heat
transfer coefficient and reducing pressure drop due limited
source of operation such as in heat exchangers, high
temperature gas turbine and electronic component.
For the enhancement of heat in a rectangular duct channel
we are using passive method of heat enhancement technique,
which is again classified in to longitudinal wise and transverse
wise heat enhancement technique. Vortex generator is one of
the method of insertion type which is found to enhancing the
heat in a variety of industrial applications.
A vortex generator is considered as a passive flow control
device which modifies the boundary layer fluid motion
bringing momentum from the outer region into the inner
region. The basic principle of vortex generator is to induce the
secondary flow which will disturb the thermal boundary layer
developed along the wall and removes heat from the wall of
Nikhil Kamlapure, Mechanical Department, JSPM’s Jayawantrao
Sawant College of Engineering, Hadapsar, Pune-28, India, 8605694880.
Prof. Shivanand Talwar, Mechanical Department, JSPM’s Jayawantrao
Sawant College of Engineering, Hadapsar, Pune-28, India, 9527788907.
Prof. Dr. P. A. Patil, Mechanical Department, JSPM’s Jayawantrao
Sawant College of Engineering, Hadapsar, Pune-28, India, 9765542844.
the duct due to turbulence. The experiments were conducted
to study the heat transfer and pressure drop in a rectangular
duct channel by using the transverse type of delta wing vortex
generator.
The experimental study on the behavior of a unique
longitudinal vortex generator embedded in a developing
turbulent boundary layer with a zero pressure gradient.[1]
At
the punched longitudinal vortex generators in the form of
winglets in staggered arrangements were used to observe the
results of vortex formation, pressure distribution, velocity
field, temperature fields, local heat transfer distribution in a
heat exchanger and the global results for the oval tubes with
two to four staggered winglets presented and compared.[2]
The comparison of fully developed heat transfer and
friction factor characteristics has been made in the rectangular
duct channel with roughened at five different shapes.[3]
The
implications of geometrical parameters of delta winglet
vortex generators on heat transfer and pressure loss
characteristics in a circular duct channel were evaluated.[4]
For the rectangular duct, the parameter examined were:
flow velocity from 0.5 to 3.4 m/s, Reynolds number from
3000 to 20,000 and results were reported with and without
mounting of the longitudinal vortex generators.[5]
The
decaying swirl flow was produced by the insertion of vortex
generators with propeller type of geometry and at three
different positions of the vortex generator in the axial
direction are examined.[6]
The heat transfer and pressure drop performance of a
full-scale heat exchanger was studied before and after
addition of wing type of vortex generators in two different
configurations and also examined the winglet configurations
at single vortex generator pair at the leading tube and three
vortex generator array placed at alternate tubes.[7]
The
experimental study of flow structure in horizontal equilateral
triangular ducts having double rows of half delta wing type of
vortex generators mounted on the duct.[8]
This paper deals
with heat transfer enhancement and pressure loss penalty
inside a rectangular duct with a delta wing type of vortex
generator.
II. DESCRIPTION OF EXPERIMENTAL SETUP
Experiments will be performed as per the figure depicted
in fig. 1. The experimental setup consists of a rectangular duct
channel of hydraulic diameter of 300mm and length of
900mm and for measuring the pressure of test section through
two pressure taps. Air blower provides air at the inlet of the
duct passed through flow control valve and an orifice-meter.
A simple U-tube manometer is used to measure the pressure
heads across the duct channel.
Experimental Study of Heat Transfer Enhancement in
a Rectangular Duct Channel with Delta Wing Vortex
Generator
Nikhil Kamlapure, Prof. Shivanand Talwar, Prof. Dr. P. A. Patil
2. Experimental Study of Heat Transfer Enhancement in a Rectangular Duct Channel with Delta Wing Vortex Generator
62 www.erpublication.org
The rectangular duct is roughened by using delta wing type
of vortex generators placed in a series and at different angle of
attack. The duct of 900mm in length is surrounded by the
heater for heating of duct and air moving inside of duct. The
vortex generators are stickled on the bottom surface of the
duct channel. These delta wing type of vortex generators are
made up of 0.5mm thick stainless sheet and placed at different
angle of attack on the bottom surface of the duct.
The high velocity air from the blower is supplied to duct
through flow control valve and orifice meter where the
pressure is given to rise. As air is leaving the orifice meter it
enters in to the rectangular duct surrounded by heating
element and gets heated. The variation in the temperature
inside the duct is measured by the fourteen thermocouples
placed on the duct surface.
Fig.1: Experimental Setup
A. Geometry of Vortex Generator
For analyzing the flow characteristics and its effect on the
heat transfer the delta wing type of vortex generator is
mounted on the bottom surface of the duct having L, H and W
along with the aspect ratio given by W/H. The parameter of
vortex generator effecting the friction factor is shown in fig.2
(Nalawade M. K., 2006).
Fig.2(a): Delta wing vortex generator
Fig.2(b): Geometry of delta wing vortex generator
Axial pitch (P): The axial distance between adjacent vortex
generators is known as pitch of the vortex generator.
Vortex generator height (e): The distance between the tip of
vortex generator to the surface of the wall where vortex
generator is mounted.
Chord length(c): The distance of tip of vortex generator to the
base of the vortex generator is known as chord length.
Vortex generator base (b): The surface of vortex generator
stickled on the wall surface of the duct is called as vortex
generator base.
B. Specifications of Setup:
1. Inner diameter of pipe (d1) = 0.06m.
2. Diameter of Orifice (d0) = 0.03m
3. Capacity of blower = 0.56h.p.
4. Range of Ammeter = 0 to 5 amp.
5. Range of Voltmeter= 0-270V ac.
6. U-tube manometer = 0-300 mm
7. Calibrated thermocouple(K type)= 00
C to 1350 0
C
8. Nichrome wire (resistivity=1.5 x 10-6
Ωm) heater
wound around test section.
C. Specification of Vortex Generator:
1. Number of Delta wing VG = 16
2. Pitch (P)= 50mm
3. Base (b) = 30mm
4. Chord length (c) = 37.5mm
5. ngle of attac 0, , 0
III. DATA REDUCTION
For investigating the heat transfer and flow friction
behaviors in a rectangular duct with the implication of
insertion of a delta wing type of vortex generators we requires
experimental calculations such as, average heat transfer
coefficients are evaluated from the local measured
temperatures and heat inputs. As heat is uniformly supplied to
the air and the temperature difference of wall surface and fluid
i.e. air (Ts−Tb), average heat transfer coefficient will be
calculated from the measured data as:
Qair = Qconv = m Cp (To-Ti) = VI
where,
Ti – inlet temperatures of air
To – outlet temperatures of air
V – Voltage supplied to the heater
I – Current supplied to the heater
Heat flux is calculated as,
q =
The experimentation was done at constant heat supply and the
calculations are performed to obtain the results. A sample
observation table is shown below showing the parameters
need to be observed during experimentation.
Table 1: Sample observation table
Sr.
No.
Temperature o
C Manometer
Difference
Orifice
Across
the duct
T1 T2 … T13 T14 hw Hw
Where,
1. T2 to T13 are the surface temperatures
2. T1 and T14 are the ambient air temperatures at inlet
and outlet of duct.
3. hw and Hw is U-tube manometer difference in mm.
4. Avg. Surface Temp.,
Ts = (T2+T3+……+T13)/12
5. Avg. Temp of air,
Tb = (T1+T14)/2
From table of properties of air required parameters can be
taken.
6. Manometer difference =water head =hw
7. Air head, ha=hw
where,
3. International Journal of Engineering and Technical Research (IJETR)
ISSN: 2321-0869 (O) 2454-4698 (P), Volume-5, Issue-4, August 2016
63 www.erpublication.org
ρw= Density of water = 1000 kg/m3
Flow rate of air through Orifice-meter,
Qa= Cd
where,
A1 = Area of pipe
Ao = Area of orifice
Cd = Co-efficient of discharge
Mass flow rate, =Qa x ρa
Velocity of air,V = Qa /A
where,
A= cross sectional area of pipe.
Heat carried out, Q = *Cp*(T14-T1)
h =
where,
h = heat transfer coefficient.
Ts = surface temperature
The Reynolds number based on duct hydraulic diameter is,
Re =
where,
V= velocity of the fluid.
Dh= Hydraulic Diameter of Duct
ν Kinematic viscosity of the fluid.
The experimental Nusselt number is calculated as:
Nu = hD/k
Where,
h = heat transfer coefficient
k = thermal conductivity of fluid
D = diameter of test section i.e. Hydra. diameter
For the internal flow if Reynolds number (Re) exceeds by
4000 then the flow is turbulent. Once the type of flow is
decided then the Nusselt number can be calculated. The
theoretical Nusselt number can be calculated (i.e. without
considering friction) and then calculated by considering
friction which will be experimental Nusselt number,
Nuth = 0.023*(Re) 0.8
*(Pr)0.4
This equation is called Dittus-Boelter equation.
fs = (1.82 log10Re-1.64
)-2
This equation is used to find friction factor called as Petukhov
equation for smooth surface.
where,
fs= Friction factor for smooth tube.
Re= Reynolds number.
The actual pressure drop & friction factor is calculated with
the help of tapping at both the ends of test pipe connected to
U-tube manometer.
The friction factor is calculated from the formula given
below:
f =
where,
ΔP pressure difference at both ends of test pipe.
L= length of test section.
The friction factor for the fully developed turbulent flow in
smooth duct (104
< Re < 106
) is given by Blasius equation as,
f = 0.046Re-0.2
The thermal performance enhancement factor, defined as the
ratio of the heat transfer coefficient of a duct with VG, h to
that of a smooth duct, ho, at an equal pumping power is given
by:
TEF η
By using above methodology for the calculation of heat
transfer and pressure drop will be carried out for determining
the heat transfer enhancement for the defined duct channel.[9]
IV. RESULTS AND DISCUSSIONS
A. Performance evaluation
The experimental results on heat transfer and friction factor
in a rectangular duct are first of all obtained for the Nusselt
number and friction factor, by using Dittus-Boelter and
Blasius equation. Meanwhile the heat loss, Reynold’s
number, heat transfer coefficient is calculated for different
angle of attack of vortex generator.
The Nusselt number ratio i.e. Nu/Nu0, defined as ratio of
implication of insertion Nusselt number to the Nusselt number
of smooth rectangular duct.
The isothermal friction factor i.e. f/f0, defined as
implication of insertion friction factor to the friction factor of
smooth rectangular duct. Finally, the graph of Reynold’s
number v/s heat transfer coefficient, Reynold’s number v/s
Nusselt number, Reynold’s number v/s friction factor were
plot to determine the thermal performance enhancement
within duct at different angle of attack of Vortex Generator
A. Reynold’s Number v/s heat transfer coefficient:
Graph 1: Re v/s h
The plot of Reynold’s number v/s heat transfer coefficient at
different angle of attac of vortex generator to discuss the heat
transfer in a duct and will be observed maximum at 0 of
vortex generator due to proper mixing of a fluid in a duct
because of the increased blockage of a fluid within the duct
will increase the mixed fluid convection and as a result the
heat transfer coefficient of a duct is increased.
B. Friction factor ratio for rectangular duct:
For the rectangular duct from the number of readings were
taken by placing the vortex generator of different angle of
attac , the friction factor value for 0, , 0 was reported and
compared in above plot. Now the friction factor for vortex
4. Experimental Study of Heat Transfer Enhancement in a Rectangular Duct Channel with Delta Wing Vortex Generator
64 www.erpublication.org
generator at different angle of attack is compared with smooth
rectangular duct without vortex generator.
Graph 2: Re v/s fcal/fb
The ratio of friction factor with vortex generator to without
vortex generator calculated by Blasius is compared to
determine the increase or decrease in friction factor for a used
insert with reference to smooth duct. If the friction factor ratio
for the inserts is low then the vortex generator is best suited
for the designed duct of defined dimensions. The graph shown
above discusses the friction factor ratio with inserts with
reference to smooth duct against the Reynold’s number.
C. Nusselt number ratio for rectangular duct:
The ratio of Nusselt number with vortex generator to
without vortex generator calculated by Dittus-Boelter is
compared to determine the increase or decrease in heat
transfer for a used insert with reference to smooth duct. If the
Nusselt number ratio for the inserts is greater then the vortex
generator is best suited for the duct of defined dimensions.
The graph shown below discusses the Nusselt number ratio
with inserts with reference to smooth duct against the
Reynold’s number.
Graph 3: Re v/s Nucal/NuDB
D. Thermal Enhancement Factor(TEF):
For the proposed test section the thermal enhancement
factor should be always more than 1, if it less than 1 then
inserts or duct is redesigned and if it is more than 1 then the
heat transfer enhancement method is preferred for the
designed duct dimensions.
Graph 4: Thermal Enhancement Factor
V. CONCLUSION
An experimental study was performed to determine the
airflow friction inside the rectangular duct, heat transfer
coefficient and enhancement in heat from the duct by, the
implication of insertions like transverse type of delta wing
vortex generator at different angle of attack. From the results
of friction factor and Nusselt number we can clearly describe
the heat transfer enhancement in a rectangular duct channel
with and without vortex generator. Amoung different angle of
attac of vortex generator the Nusselt number, Reynold’s
number, heat transfer coefficient and friction factor variation
was seen best suited at an angle of 0 of vortex generator.
Meanwhile the Thermal Enhancement Factor(TEF) was also
found to be highest at lower Reynold’s number.
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[1] Shakaba, Mehta R. D., and Bradshaw P., (1985), Longitudinal
vortices embedded in turbulent boundary layers. Part 1. Single vortex,
J. Fluid Mech., Vol. 155, pp 37-57.
[2] Chen Y, Fiebig M, Mitra N.K, (2000), Heat transfer enhancement of
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[3] Ahn S. W., (2001), The effect of roughness types on friction factors
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[5] Qiuwang Wang, Qiuyang Chena, Ling Wang, Min Zenga, Yanping
Huangc, Zejun Xiao, (2007), Experimental study of heat transfer
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[7] Joardar A, Jacobi A.M., (2008), Heat transfer enhancement by
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[8] Azize Akcayoglu, (2010), Flow past confined delta-wing type vortex
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[9] Pongjet Promvonge, Sompol Skullong, Sutapat Kwankaomeng,
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617–624.
Nikhil Kamlapure is pursuing his Post Graduation in Heat-Power
(Mechanical Department) from JSPM’s Jayawantrao Sawant College of
Engineering, Hadapsar, Pune-28, India. He has completed his B.E. from
University of Pune in 2014.
Prof. Shivanand Talwar is Assistant Professor in Department of
Mechanical Engg., JSPM’s Jayawantrao Sawant College of Engineering,
Hadapsar, Pune-28, India. He has 05 years of teaching experience and 01
year industrial experience. He has completed his M.Tech (Thermal) form
VTU Belgaon, India.
Prof. Dr. P. A. Patil is Head of Mechanical Engineering Department,
JSPM’s Jayawantrao Sawant College of Engineering, Hadapsar, Pune-28,
India. He has 19 years of teaching and 1 year industrial experience. His area
of specialization is in Refrigeration and Air-Conditioning, Fluid Mechanics
and Heat Transfer.