A numerical investigation of heat transfer
characteristics of pulsating turbulent flow in a circular
tube is carried out. The flow is thermally and
hydrodynamically fully developed and the tube wall is
subjected to a uniform heat flux. The flow inlet to the
pipe consists of fixed component and pulsating
component that varies sinusoidally with time. The flow
and temperature fields are computed numerically using
computational fluid dynamics (CFD) Fluent code.
Prediction of heat transfer characteristics is performed
over a range of 10 4 ≤ Re ≤ 4x10 4 and 0 ≤ ƒ ≤ 70 are
observed. Results showed little reduction in the mean
time-averaged Nusselt number with respect to that of
steady flow. However, in the fully developed
established region, the local Nusselt number either
increases or decreases over the steady flow-values
depending on the frequency parameter. These noticed
deviations are rather small in magnitude for the
computed parameter ranges. The characteristics of heat
transfer are qualitatively consistent with the available
experimental and numerical predictions.
Obtain average velocity from a knowledge of velocity profile, and average temperature from a knowledge of temperature profile in internal flow.
Have a visual understanding of different flow regions in internal flow, and calculate hydrodynamic and thermal entry lengths.
Analyze heating and cooling of a fluid flowing in a tube under constant surface temperature and constant surface heat flux conditions, and work with the logarithmic mean temperature difference.
Obtain analytic relations for the velocity profile, pressure drop, friction factor, and Nusselt number in fully developed laminar flow.
Determine the friction factor and Nusselt number in fully developed turbulent flow using empirical relations, and calculate the heat transfer rate.
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.
technoloTwo dimensional numerical simulation of the combined heat transfer in...ijmech
A numerical investigation was conducted to analyze the flow field and heat transfer characteristics in a vertical channel withradiation and blowing from the wall. Hydrodynamic behaviour and heat transfer results are obtained by the solution of the complete Navier–Stokesand energy equations using a control volume finite element method. Turbulent flow with "Low Reynolds Spalart-Allmaras Turbulence Model" and radiation with "Discrete Transfer Radiation Method" had been modeled. In order to have a complete survey, this article has a wide range of study in different domains including velocity profiles at different locations, turbulent viscosity, shear stress, suctioned mass flow rate in different magnitude of the input
Rayleigh number, blowing Reynoldsnumber, radiation parameter, Prandtl number, the ratio of length to width and also ratio of opening thickness to width of the channel. In addition, effects of variation in any of the above non-dimensional numbers on parameters of the flow are clearly illustrated. At the end resultants had been compared with experimental data which demonstrated that in the present study, results have a great accuracy, relative errors are very small and the curve portraits are in a great
agreement with real experiments.
Learn about Conduction, Convection, Radiation and Heat exchangers in a most comprehensive and interactive way. Derivations of formulas, concepts, Numerical, examples are inculcated in the course with advance applications. The course aims at covering all the topics and concepts of HMT as per academics of students. Following are the topics (in detail) that will be covered in the course.
Conduction
Thermal conductivity, Heat conduction in gases, Interpretation Of Fourier's law, Electrical analogy of heat transfer, Critical radius of insulation, Heat generation in a slab and cylinder, Fins, Unsteady/Transient conduction.
Convection
Forced convection heat transfer, Reynold’s Number, Prandtl Number, Nusselt Number, Incompressible flow over flat surface, HBL, TBL, Forced convection in flow through pipes and ducts, Free/Natural convection.
Heat Exchangers
Types of heat exchangers, First law of thermodynamics, Classification of heat exchangers, LMTD for parallel and counter flow, NTU, Fouling factor.
Radiation
Absorbtivity, Reflectivity, Transmitivity, Laws of thermal radiation, Shape factor, Radiation heat exchange
COPY-PASTE below URL to ENROLL in the COMPLETE course & see the hidden contents with proper explanations.
https://www.udemy.com/course/heat-and-mass-transfer
Obtain average velocity from a knowledge of velocity profile, and average temperature from a knowledge of temperature profile in internal flow.
Have a visual understanding of different flow regions in internal flow, and calculate hydrodynamic and thermal entry lengths.
Analyze heating and cooling of a fluid flowing in a tube under constant surface temperature and constant surface heat flux conditions, and work with the logarithmic mean temperature difference.
Obtain analytic relations for the velocity profile, pressure drop, friction factor, and Nusselt number in fully developed laminar flow.
Determine the friction factor and Nusselt number in fully developed turbulent flow using empirical relations, and calculate the heat transfer rate.
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.
technoloTwo dimensional numerical simulation of the combined heat transfer in...ijmech
A numerical investigation was conducted to analyze the flow field and heat transfer characteristics in a vertical channel withradiation and blowing from the wall. Hydrodynamic behaviour and heat transfer results are obtained by the solution of the complete Navier–Stokesand energy equations using a control volume finite element method. Turbulent flow with "Low Reynolds Spalart-Allmaras Turbulence Model" and radiation with "Discrete Transfer Radiation Method" had been modeled. In order to have a complete survey, this article has a wide range of study in different domains including velocity profiles at different locations, turbulent viscosity, shear stress, suctioned mass flow rate in different magnitude of the input
Rayleigh number, blowing Reynoldsnumber, radiation parameter, Prandtl number, the ratio of length to width and also ratio of opening thickness to width of the channel. In addition, effects of variation in any of the above non-dimensional numbers on parameters of the flow are clearly illustrated. At the end resultants had been compared with experimental data which demonstrated that in the present study, results have a great accuracy, relative errors are very small and the curve portraits are in a great
agreement with real experiments.
Learn about Conduction, Convection, Radiation and Heat exchangers in a most comprehensive and interactive way. Derivations of formulas, concepts, Numerical, examples are inculcated in the course with advance applications. The course aims at covering all the topics and concepts of HMT as per academics of students. Following are the topics (in detail) that will be covered in the course.
Conduction
Thermal conductivity, Heat conduction in gases, Interpretation Of Fourier's law, Electrical analogy of heat transfer, Critical radius of insulation, Heat generation in a slab and cylinder, Fins, Unsteady/Transient conduction.
Convection
Forced convection heat transfer, Reynold’s Number, Prandtl Number, Nusselt Number, Incompressible flow over flat surface, HBL, TBL, Forced convection in flow through pipes and ducts, Free/Natural convection.
Heat Exchangers
Types of heat exchangers, First law of thermodynamics, Classification of heat exchangers, LMTD for parallel and counter flow, NTU, Fouling factor.
Radiation
Absorbtivity, Reflectivity, Transmitivity, Laws of thermal radiation, Shape factor, Radiation heat exchange
COPY-PASTE below URL to ENROLL in the COMPLETE course & see the hidden contents with proper explanations.
https://www.udemy.com/course/heat-and-mass-transfer
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
SPLIT SECOND ANALYSIS COVERING HIGH PRESSURE GAS FLOW DYNAMICS AT PIPE OUTLET...AEIJjournal2
A detailed investigation covering piped gas flow characteristics in high pressure flow conditions. Such flow analysis can be resolved using established mathematical equations known as the Fanno condition, which usually cover steady state, or final flow conditions. However, in real life, such flow conditions are
transient, varying with time. This paper uses CFD analysis providing a split second “snapshot” at what happens at the pipe outlet, and therefore, a closer understanding at what happens at the pipe’s outlet in high pressure gas flow condition
Effect on heat transfer for laminar flow over Backward Facing Step with squar...ijceronline
The purpose of this paper is to study the influence of an adiabatic square cylinder on the heat transfer enhancement in the 2D laminar flow over the Backward Facing Step (BFS). This work also studies the effect of streamwise position of the square cylinder on heat transfer enhancement. The governing equations, for the 2D laminar flow over BFS with a square cylinder placed inside, are solved on nonuniform Cartesian grid using projection method. The individual differential terms of the N-S equations are discretized using a Higher Order Compact Scheme (HOCS). The numerical code is first validated with the results available in the literature. The main advantage of HOCS is to obtain higher order approximations to the derivatives accurately without the necessity of higher number of nodes. Thus reducing the computational cost. It is observed from the numerical experiment that placing the cylinder affects the fluid flow and heat transfer and for XC=1.4, YC = 1.0 and Re= 200, there is a maximum heat transfer enhancement of 193.93%.The results of these numerical experiments are useful in studying the heat transfer enhancement and its dependence on the bluff body and flow characteristics. This work has its applications in engineering problems where the heat transfer in a laminar flow regime can be enhanced using a bluff body. The current work also demonstrates the dependence of horizontal position of cylinder on heat transfer augmentation.
Experiment on single-mode feedback control of oscillatory thermocapillary con...IJERA Editor
Feedback control was carried out on nonlinear thermocapillary convections in a half-zone liquid bridge of a high
Prandtl number fluid under normal gravity. In the liquid bridge, the convection changed from a two-dimensional
steady flow to a three-dimensional oscillatory flow at a critical temperature difference. Feedback control was
realized by locally modifying the free surface temperature using local temperature measured at different
positions. The present study aims to confirm whether the control method can effectively suppress oscillatory
flows with every modal structure. Consequently, the control was theoretically verified to be effective for
oscillatory flows with every modal structure in a high Marangoni number range.
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFERFROM SQUARE CYLIND...ijmech
The enhancement of natural convection heat transfer using nanofluids from horizontal square cylinder
placed in a square enclosure is investigated numerically. Water-based Cu is used as the working nanofluid.
The investigation covered a range of Rayleigh numbers of 104
- 106
, nanoparticles volume fraction of
(0<ϕ≤0.2), enclosure width to cylinder height ratio, W/H of 2.5. The investigation includes the solution of
the governing equations in the Vorticity-Stream function space with the aid of a body fitted coordinate
system. Algebraic grid generation is used in the initial transformations, followed by an elliptic
transformation to complete the grid generation to computational domain. The resulting discretized system
of equations is solved using an ADI method. The built code is validated and the results showed an increase
in average Nusselt number with increasing the volume fraction of the nanoparticles for the whole range of
Rayleigh number. The isotherms are nearly similar when the volume fraction of nanoparticles is increased
from 0 to 0.2 for each Rayleigh number but a change in the streamlines is observed.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed
Boiling and Condensation heat transfer -- EES Functions and Procedurestmuliya
This file contains notes on Engineering Equation Solver (EES) Functions and Procedures for Boiling and Condensation heat transfer. Some problems are also included.
These notes were prepared while teaching Heat Transfer course to the M.Tech. students in Mechanical Engineering Dept. of St. Joseph Engineering College, Vamanjoor, Mangalore, India.
Contents: Summary of formulas used -
EES Functions/Procedures for boiling: Nucleate boiling heat flux for any geometry - critical heat flux for large horizontal surface, horizontal cylinder and sphere - Film boiling for horizontal cylinder, sphere and horizontal surface – Problems.
EES Functions/Procedures for condensation of: steam on vertical surface – any fluid on a vertical surface – steam on vertical cylinder – any fluid on vertical cylinder – steam on horizontal cylinder – any fluid on horizontal cylinder – steam on a horizontal tube bank – any fluid on horizontal tube bank – any fluid on a sphere – any fluid inside a horizontal cylinder - Problems.
It is hoped that these notes will be useful to teachers, students, researchers and professionals working in this field.
NUMERICAL INVESTIGATION OF LAMINAR NANOFLUID FLOW IN MICRO CHANNEL HEAT SINKS IAEME Publication
The effect of using nanofluids on heat transfer and aerodynamics characteristics in rectangular shaped micro channel heat sink (MCHS) is numerically investigated for Reynolds number range of (100-400 ) and different value of heat flux (50 , 100, 150 ) / . In this study,the MCHS performance using tow type of nanofluid with volume
fraction 10% was used as a coolant is examined. The three-dimensional steady, laminar flow and heat transfer governing equations are solved using The computational fluid dynamics code (FLUENT). The MCHS performance is evaluated in terms of temperature profile, heat transfer,velocity profile, pressure drop and friction factor.
Thermohydraulic Performance of a Series of In-Line Noncircular Ducts in a Par...Carnegie Mellon University
Heat transfer and fluid flow characteristics for two-dimensional laminar flow at low Reynolds number for five in-line ducts of
various nonconventional cross-sections in a parallel plate channel are studied in this paper.The governing equations were solved
using finite-volumemethod.CommercialCFDsoftware,ANSYS Fluent 14.5,was used to solve this problem.Atotal of three different
nonconventional, noncircular cross-section ducts and their characteristics are compared with those of circular cross-section ducts.
Shape-2 ducts offered minimum flow resistance and maximum heat transfer rate most of the time. Shape-3 ducts at Re < 100 and Shape-2 ducts at Re > 100 can be considered to give out the optimum results.
I am Moffat K. I am a Hydraulic Engineering Assignment Expert at eduassignmenthelp.com. I hold a Ph.D. in Engineering, from Harvard University, USA. I have been helping students with their assignments for the past 8 years. I solve assignments related to Hydraulic Engineering.
Visit eduassignmenthelp.com or email info@eduassignmenthelp.com. You can also call on +1 678 648 4277 for any assistance with Hydraulic Engineering Assignments.
Second Law Analysis of Fluid Flow and Heat Transfer through Porous Channel wi...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Numerical Analysis of heat transfer in a channel Wit in clined bafflesinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
SPLIT SECOND ANALYSIS COVERING HIGH PRESSURE GAS FLOW DYNAMICS AT PIPE OUTLET...AEIJjournal2
A detailed investigation covering piped gas flow characteristics in high pressure flow conditions. Such flow analysis can be resolved using established mathematical equations known as the Fanno condition, which usually cover steady state, or final flow conditions. However, in real life, such flow conditions are
transient, varying with time. This paper uses CFD analysis providing a split second “snapshot” at what happens at the pipe outlet, and therefore, a closer understanding at what happens at the pipe’s outlet in high pressure gas flow condition
Effect on heat transfer for laminar flow over Backward Facing Step with squar...ijceronline
The purpose of this paper is to study the influence of an adiabatic square cylinder on the heat transfer enhancement in the 2D laminar flow over the Backward Facing Step (BFS). This work also studies the effect of streamwise position of the square cylinder on heat transfer enhancement. The governing equations, for the 2D laminar flow over BFS with a square cylinder placed inside, are solved on nonuniform Cartesian grid using projection method. The individual differential terms of the N-S equations are discretized using a Higher Order Compact Scheme (HOCS). The numerical code is first validated with the results available in the literature. The main advantage of HOCS is to obtain higher order approximations to the derivatives accurately without the necessity of higher number of nodes. Thus reducing the computational cost. It is observed from the numerical experiment that placing the cylinder affects the fluid flow and heat transfer and for XC=1.4, YC = 1.0 and Re= 200, there is a maximum heat transfer enhancement of 193.93%.The results of these numerical experiments are useful in studying the heat transfer enhancement and its dependence on the bluff body and flow characteristics. This work has its applications in engineering problems where the heat transfer in a laminar flow regime can be enhanced using a bluff body. The current work also demonstrates the dependence of horizontal position of cylinder on heat transfer augmentation.
Experiment on single-mode feedback control of oscillatory thermocapillary con...IJERA Editor
Feedback control was carried out on nonlinear thermocapillary convections in a half-zone liquid bridge of a high
Prandtl number fluid under normal gravity. In the liquid bridge, the convection changed from a two-dimensional
steady flow to a three-dimensional oscillatory flow at a critical temperature difference. Feedback control was
realized by locally modifying the free surface temperature using local temperature measured at different
positions. The present study aims to confirm whether the control method can effectively suppress oscillatory
flows with every modal structure. Consequently, the control was theoretically verified to be effective for
oscillatory flows with every modal structure in a high Marangoni number range.
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFERFROM SQUARE CYLIND...ijmech
The enhancement of natural convection heat transfer using nanofluids from horizontal square cylinder
placed in a square enclosure is investigated numerically. Water-based Cu is used as the working nanofluid.
The investigation covered a range of Rayleigh numbers of 104
- 106
, nanoparticles volume fraction of
(0<ϕ≤0.2), enclosure width to cylinder height ratio, W/H of 2.5. The investigation includes the solution of
the governing equations in the Vorticity-Stream function space with the aid of a body fitted coordinate
system. Algebraic grid generation is used in the initial transformations, followed by an elliptic
transformation to complete the grid generation to computational domain. The resulting discretized system
of equations is solved using an ADI method. The built code is validated and the results showed an increase
in average Nusselt number with increasing the volume fraction of the nanoparticles for the whole range of
Rayleigh number. The isotherms are nearly similar when the volume fraction of nanoparticles is increased
from 0 to 0.2 for each Rayleigh number but a change in the streamlines is observed.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed
Boiling and Condensation heat transfer -- EES Functions and Procedurestmuliya
This file contains notes on Engineering Equation Solver (EES) Functions and Procedures for Boiling and Condensation heat transfer. Some problems are also included.
These notes were prepared while teaching Heat Transfer course to the M.Tech. students in Mechanical Engineering Dept. of St. Joseph Engineering College, Vamanjoor, Mangalore, India.
Contents: Summary of formulas used -
EES Functions/Procedures for boiling: Nucleate boiling heat flux for any geometry - critical heat flux for large horizontal surface, horizontal cylinder and sphere - Film boiling for horizontal cylinder, sphere and horizontal surface – Problems.
EES Functions/Procedures for condensation of: steam on vertical surface – any fluid on a vertical surface – steam on vertical cylinder – any fluid on vertical cylinder – steam on horizontal cylinder – any fluid on horizontal cylinder – steam on a horizontal tube bank – any fluid on horizontal tube bank – any fluid on a sphere – any fluid inside a horizontal cylinder - Problems.
It is hoped that these notes will be useful to teachers, students, researchers and professionals working in this field.
NUMERICAL INVESTIGATION OF LAMINAR NANOFLUID FLOW IN MICRO CHANNEL HEAT SINKS IAEME Publication
The effect of using nanofluids on heat transfer and aerodynamics characteristics in rectangular shaped micro channel heat sink (MCHS) is numerically investigated for Reynolds number range of (100-400 ) and different value of heat flux (50 , 100, 150 ) / . In this study,the MCHS performance using tow type of nanofluid with volume
fraction 10% was used as a coolant is examined. The three-dimensional steady, laminar flow and heat transfer governing equations are solved using The computational fluid dynamics code (FLUENT). The MCHS performance is evaluated in terms of temperature profile, heat transfer,velocity profile, pressure drop and friction factor.
Thermohydraulic Performance of a Series of In-Line Noncircular Ducts in a Par...Carnegie Mellon University
Heat transfer and fluid flow characteristics for two-dimensional laminar flow at low Reynolds number for five in-line ducts of
various nonconventional cross-sections in a parallel plate channel are studied in this paper.The governing equations were solved
using finite-volumemethod.CommercialCFDsoftware,ANSYS Fluent 14.5,was used to solve this problem.Atotal of three different
nonconventional, noncircular cross-section ducts and their characteristics are compared with those of circular cross-section ducts.
Shape-2 ducts offered minimum flow resistance and maximum heat transfer rate most of the time. Shape-3 ducts at Re < 100 and Shape-2 ducts at Re > 100 can be considered to give out the optimum results.
I am Moffat K. I am a Hydraulic Engineering Assignment Expert at eduassignmenthelp.com. I hold a Ph.D. in Engineering, from Harvard University, USA. I have been helping students with their assignments for the past 8 years. I solve assignments related to Hydraulic Engineering.
Visit eduassignmenthelp.com or email info@eduassignmenthelp.com. You can also call on +1 678 648 4277 for any assistance with Hydraulic Engineering Assignments.
Second Law Analysis of Fluid Flow and Heat Transfer through Porous Channel wi...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Numerical Analysis of heat transfer in a channel Wit in clined bafflesinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Numerical Investigation of Mixed Convective Flow inside a Straight Pipe and B...iosrjce
The present study deals with a numerical investigation of steady laminar and turbulent mixed
convection heat transfer in a horizontal pipe and bend pipe using air as the working fluid.The thermal boundary
condition chosen is that of uniform temperature at the outer wall. Computations were performed to investigate
the effect of inlet Rayleigh number and Reynolds number in the velocity and temperature profile at inside of the
pipe. The secondary flow is more intense in the upper part of the cross-section. It increases throughout the
cross-section until its intensity reaches a maximum, and then it becomes weak at far downstream. For the
horizontal pipe the value of the L/D ratio becomes more than 10 the secondary flow effects are neutralized and
the velocity profile almost become constant throughout.
Effects of Variable Viscosity and Thermal Conductivity on MHD free Convection...theijes
A steady two-dimensional MHD free convection and mass transfer flow past an inclined vertical surface in the presence of heat generation and a porous medium have been studied numerically when the fluid viscosity and thermal conductivity are assumed to be vary as inverse linear function of temperature. The governing partial differential equations are reduced to a system of ordinary differential equations by introducing similarity transformations. The non-linear similarity equations are solved numerically by applying the Runge-Kutta method of fourth order with shooting technique. The numerical results are presented graphically to illustrate influence of different values of the parameters on the velocity, temperature and concentration profiles. Skin friction, Nusselt number and Sherwood number are also completed and presented in tabular form.
Pressure and Heat Transfer over a Series of In-line Non-Circular Ducts in a P...Carnegie Mellon University
Flow and heat transfer for two-dimensional laminar flow at low Reynolds number for five in-line ducts of various cross-sections in a parallel plate channel are studied in this paper. The governing equations were solved using finite-volume method. A commercial CFD software, ANSYS Fluent 14.5 was used to solve this problem. A total of three different non-conventional cross-sections and their characteristics are compared with that of circular cross-section. Shape-1, Shape-2 and Shape-3 performed better for heat transfer rate than the circular cross-section, but also offered higher resistance to the flow. Shape-1 offered less resistance to flow at Re < 200 but post Re = 200 the resistance equalled to that of the Shape-3. In overall, Shape-2 performed better when the heat transfer and resistance to flow were considered.
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.
Heat Transfer Analysis of Refrigerant Flow in an Evaporator TubeIJMER
the paper aim is to presenting the heat transfer analysis of refrigerant flow in an evaporator
tube is done. The main objective of this paper is to find the length of the evaporator tube for a pre-defined
refrigerant inlet state such that the refrigerant at the tube outlet is superheated. The problem involves
refrigerant flowing inside a straight, horizontal copper tube over which water is in cross flow. Inlet
condition of the both fluids and evaporator tube detail except its length are specified. here pressure and
enthalpy at discrete points along the tube are calculated by using two-phase frictional pressure drop model.
Predicted values were compared using another different pressure drop model. A computer-code using
Turbo C has been developed for performing the entire calculation
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Numerical Simulation on Mixed Convection Flow within Triangular Enclosures Ha...IOSR Journals
This paper is conducted to investigate mixed convection flow within triangular enclosures having heatline concept. Here the left vertical wall which is moving from the bottom corner of the enclosure is also kept at a uniform constant cold temperature and the bottom wall is heat generating, while the other inclined wall is adiabatic. A finite element analysis is performed for solving the governing equations which are discretized by Galerkin weighted residual method of finite element formulation. The present numerical procedure adopted in this investigation yields consistent performance over a wide range of parameters Prandtl number, Pr (Pr = 0.71 - 6) varying Rayleigh number (Ra) from 103 to 104 while Reynolds number, Re (Re = 50) is fixed. The Result also indicates streamlines, isotherms, average Nusselt number along the hot wall, average temperature of the fluid in the enclosure. The computational results also indicate that the average Nusselt number at the hot wall of the Enclosure is depending on the dimensionless parameters.
TWO FLUID ELECTROMAGNETO CONVECTIVE FLOW AND HEAT TRANSFER BETWEEN VERTICAL W...IAEME Publication
The mixture of viscous and magneto convective flow and heat transfer between a long vertical wavy wall and a parallel flat wall in the presence of applied electric field parallel to gravity , magnetic field normal to gravity in the presence of source or sink is investigated. The non-linear equations governing the flow are solved using the linearization technique. The effect of Grash of number and width ratio is to promote the flow for both open and short circuits. The effect of Hartmann number is to suppress the flow, the effect of source is to promote and the effect of sink is to suppress the velocity for open and short circuit s. Conducting ratio decreases the temperature where as width ratio increases the temperature.
Similar to Numerical study of heat transfer in pulsating turbulent air flow (20)
A comprehensive review on passive heat transfer enhancementsMohamed Fadl
Enhancing heat transfer surface are used in many engineering applications such as heat exchanger, air
conditioning, chemical reactor and refrigeration systems, hence many techniques have been investi-
gated on enhancement of heat transfer rate and decrease the size and cost of the involving equipment
especially in heat exchangers. One of the most important techniques used are passive heat transfer
technique. These techniques when adopted in Heat exchanger proved that the overall thermal
performance improved significantly. This paper reviews experimental and numerical works taken by
researchers on this technique since 2004 such as twisted tape, wire coil, swirl flow generator, y etc. to
enhance the thermal efficiency in heat exchangers and useful to designers implementing passive
augmentation techniques in heat exchange. The authors found that variously developed twisted tape
inserts are popular researched and used to strengthen the heat transfer efficiency for heat exchangers.
The other techniques used for specific work environments are studied in this paper. Twisted tape
inserts perform better in laminar flow than turbulent flow. However, the other several passive
techniques such as ribs, conical nozzle, and conical ring, etc. are generally more efficient in the
turbulent flow than in the laminar flow.
Cfd simulation for wind comfort and safetyMohamed Fadl
Concern towards the quality of public urban areas has increased in recent years. Wind comfort and
safety in pedestrian areas has become one important environmental parameter when designing new cities. Hence,
architects and town planners need guidelines and simplified design tools to take account of the wind in their
projects. The objectives of this study provide more insight in the pedestrian living conditions around the Hub, a
newly built structure, part of Coventry University campus and at the same time study the influence of building
shapes on the wind distribution. The latter is based on a series of computational fluid dynamics simulations
(CFD), used to advise the University’s Estates Department of the possibility of wind nuisance around the central
campus area. The velocity field was computed using the finite volume method. The simulations were performed
for different wind speeds and directions. The predicted results showed that the distribution of the velocity field
varied and had different characteristics with different wind directions. Also, it was established that the wind
speed amplification factors in diverging passages were generally larger than those in converging passages. The
case study incorporated is intended to support and guide future studies of wind comfort and safety with CFD
and thus makes a modest contribution in improving wind environmental quality in urban areas.
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.
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• 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.
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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.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
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Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
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.
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.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
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.
2. Numerical study of heat transfer in pulsating turbulent air flow, E. A.M.Elshafei et al.
ThETA01/06864
2.2 The Governing Conservation Equations
The governing equations for transient turbulent
incompressible flow and heat transfer in the flow region
(0 ≤ x ≤ L and 0 ≤ r ≤ R) can be written as follows [32]:
Continuity:
0
∂∂
∂
=
∂
++
r
v
r
v
x
u
(1)
Momentum in x-direction:
.
1
3
2
2
1
∂
∂
-
)(
∂
∂1
)(
∂
∂1
∂
∂
∂
∂
+
∂
∂
∂
∂
+
+
∂
∂
+
∂
∂
−
∂
∂
∂
∂
+=
++
x
v
r
u
r
rr
r
v
r
v
x
u
x
u
r
xrx
p
rvu
rr
ruu
xrt
u
µ
µ
ρ
Momentum in r-direction:
( ) ( )
.
3
2
2
3
2
2
1
1
11
2
+
∂
∂
+
∂
∂
+−
+
∂
∂
+
∂
∂
−
∂
∂
∂
∂
+
∂
∂
+
∂
∂
∂
∂
+
∂
∂
−=
∂
∂
+
∂
∂
+
∂
∂
r
v
r
v
x
u
rr
v
r
v
r
v
x
u
r
v
r
rr
r
u
x
v
r
rrr
P
rvv
rr
ruv
xrt
v
µ
µ
µ
µ
ρ
Energy:
φ
r
T
r
rrx
T
r
T
v
x
T
u
t
T
Cp
eff µλ
ρ
+
∂
∂
∂
∂
+
∂
∂
=
++
1
∂
∂
∂
∂
∂
∂
2
2
Where φ is viscous dissipation term, which is
φ
and λeff is the effective thermal conductivity, and for
standard k-ε model, is given by
λeff = λ+ λt (3. c),
λt = Cp µt /Prt (3. d)
2.3 Turbulence Model
Among the available turbulent models, those based on
eddy viscosity are widely applied to the turbulent
kinetic energy – turbulent energy dissipation rate (k-ε).
Two additional equations for the standard k-ε turbulence
model: the turbulence kinetic energy, k, and the
dissipation rate, ε, are determine using the following
transport equations, respectively.
k – Equation:
Where
ε- equation:
( )ρε
ε
ε
σ
µ
µ
ε
σ
µ
µ
ε
ρ
εε
εε
21
∂
∂
∂
∂1
∂
∂
∂
∂
CGC
k
r
r
rrxxDt
D tt
−+
++
+=
The turbulent viscosity, µt is computed by combining K
- ε as follows:
)/( 2
ερµ µ kCt = (6)
Cµ, C1ε, and C2ε are the model constant; σk and σε are
turbulent Prandtl numbers for k and ε, respectively.
They have the following default values (Launder
&Spalding 1972): Cµ= 0.09, C1ε= 1.44, C2ε= 1.92, σk
=1.0, σε=1.3,
(3.a)
(2.a)
(2.b)
Uin
T in
Entrance length (2.6 m)
Symmetry axis
Fluid
(Air)
Pipe wall
R
L heated (1.16 m)
x
Uniform wall heat flux q"
r
Fig. 1 Schematic diagram for the studied problem.
,2
222
∂
∂
+
∂
∂
+
+
∂
∂
+
∂
∂
=
r
u
x
v
r
v
r
v
x
u
(4.a)
ρε
σ
µ
µ
σ
µ
µρ
-
∂
∂
∂
∂1
∂
∂
∂
∂
G
r
k
r
rr
x
k
xDt
Dk
k
t
k
t
+
++
+=
(4.b)
++
+
+
=
2222
∂
∂
∂
∂
2
∂
∂
2
∂
∂
2
x
v
r
u
r
v
r
v
x
u
G tµ
0
10
20
30
40
50
U(t)[m/s]
Um
UA
Л 2Л
Fig .2. Variations of inlet velocity
(3.b)
(5)
3. Numerical study of heat transfer in pulsating turbulent air flow, E. A.M.Elshafei et al.
ThETA01/068 65
2-4 Heat Transfer Coefficient and Nusselt
Number
Due to the unique characteristics of the pulsating flow,
several heat transfer coefficients have to be carefully
defined.
The instantaneous local heat transfer coefficient is given
by
avw TT
txh
-
q′′
=),( (7-a),
and the local heat transfer coefficient, defined as the
average of heat transfer coefficient over a cycle, is
formulated as
∫=
π
ω
π
2
0
)( )(
2
1
thdh xx (7-b)
The instantaneous heat transfer coefficient, defined as
the average of heat transfer coefficient over the whole
length of pipe at a given moment, is expressed as
∫=
L
tt hdx
L
h
0
)( .
1
(7-c)
Subsequently, several relevant Nusselt numbers are
rationally introduced. The instantaneous local Nusselt
number is
K
hD
txNu tx =),(, (7-d)
The overall Nusselt number; Nu is given by
∫ ∫=
L
tx dxtdNu
L
Nu
0
2
0
, .)(
2
1
π
ω
π
(7-e)
To ensure sufficient temporal resolution of the
numerical solution, five to seven cycles are required to
obtain a steady periodic solution with an acceptable
accuracy.
2-5 Boundary Conditions
The solution domain of the considered 2D,
axisymmetric pipe flow is geometrically quite simple,
which is a rectangle on the x-r plane, enclosed by the
inlet, outlet, symmetry and wall boundaries .On walls
no-slip condition are assumed for the momentum
equations. The inlet velocity values have been derived
from given Reynolds numbers. Inaccuracies due to an
uncertainty in the shape of the inlet velocity profiles are
not expected to play an important role, since all
calculations were carried out at places sufficiently down
stream from the inlet, so that quite fully-developed
conditions should be expected at the calculating section.
For pulsating cases, the inlet velocity is varied with
time. The outlet boundary condition is called "outflow",
which implies zero-gradient condition at the outlet.
At the pipe inlet, (x=0):
For steady flow condition, U (t) = Uin, and for
sinusoidal pulsating flow, U (t) = Um+ UA sin (ωt)
At the pipe exit plane, (x = L):
At the pipe axis, (r = 0):
At the pipe wall, (r = R): (u, v k, ε) = 0, a uniform heat
flux is imposed, q" = qο for heated section and q" = 0
for the adiabatic wall.
Values of k and ε are not known at the inlet, but, if they
are not given by experimental data, some reasonable
assumptions can be made. The kinetic energy of
turbulence according to a certain value of the square of
the average inlet velocity is expressed by [ 33]
k=0.03 Uin
2
In addition, dissipation is calculated according to the
equation
R
k
C
03.0
2
3
µε =
2-6 Simulation Values
In the analysis, the following simulation values are
taken as:
Uin = (12.7 to 42.8) m/s, Um =11.07 m/s
UA = (1.63 to 31.81) m/s, ω = (41.9 to 427.25) rad/s,
and qο =922 W/m2
3- COMPUTATIONAL PROCEDURE
3-1 Calculation Tools
Even the difficult general differential equations now
yield to the approximating technique known as
numerical analysis, whereby the derivates are simulated
by algebraic relations between a finite numbers of grid
points in the flow field which are then solved on a
digital computer. A suitable CFD computer code is used
to solve the governing equations numerically along with
the boundary and the initial conditions. The CFD
program is a process by which the fluid flow
characteristics can be predicted through arbitrary
geometries giving such information as: flow speed,
pressure, residence time, flow patterns, etc. The Fluent
6·1 (Fluent 2003) program is chosen as the CFD
computer code for this work because of the ease with
which the analysis model can be created, and because
the software allows users to modify the code for special
analysis conditions through the use of user subroutines.
The Fluent computer code uses a finite-volume
procedure to solve the governing equations of fluid flow
in primitive variables such as velocity components in
0=
∂
∂
r
φ
0=
∂
∂
x
φ
4. Numerical study of heat transfer in pulsating turbulent air flow, E. A.M.Elshafei et al.
ThETA01/06866
axial and radial directions and pressure. A variety of
turbulence models is offered by the Fluent computer
code. The standard k–ε model was used as a turbulence
model in this study. This model is a semi-empirical one,
based on model transport equations for the turbulent
kinetic energy (k) and its dissipation rate (ε). The model
transport equation for k is derived from the exact
equation while the model transport equation for ε is
obtained using physical reasoning and bears little
resemblance to its mathematically exact counterpart. In
the derivation of the k–ε model, it was assumed that the
flow is fully turbulent, and the effects of molecular
viscosity are negligible. The standard k–ε model is,
therefore, valid only for fully turbulent flows. A detailed
description of turbulence models and its applications to
turbulence can be found in "Fluent 2003; Launder &
Spalding 1972". In the case of the standard k–ε models,
two additional transport equations, (for the turbulent
kinetic energy and the turbulence dissipation rate) are
solved, and turbulent viscosity, µt, is computed as a
function of k and ε. The solution method for this study
is axisymmetric. In order to define the pulsating inlet
velocities in all cases, an UDF (User-Defined Function)
file was introduced to the prepared fluent case file. By
using the results of the calculations performed with the
fluent code. This program, written in FORTRAN 77
language, calculates numerically the local and average
Nusselt Number.
Grid size: Grid-independent tests were carried out to
ensure grid independence of the calculated results;
consequently, the grid size and the grid orientation
giving grid independent results were selected, and thus a
total cell number of 45000 cells (300× 150) were
adopted. The grid points are clustered in the radial
direction so that the finer spacing is formed near the
wall and at the inlet. Fig.3 shows the grid.
4- RESULTS AND DISCUSSION
4-1 Steady Flow
To validate the numerical calculations, the
computational results for the fully developed steady
turbulent pipe flow are compared with the experimental
data observed by Elshafei et al. [31]. For two different
values of Reynolds number, the numerical results are in
consistent with the experimental results; within about
±5 % as can be noticed in Fig 4. The flow was
observed to be thermally fully developed for X/D ≥ 20.
4-2 Pulsating Flow
In the present work, investigations are performed within
the ranges of 104
≤ Re ≤ 4x104
, and 0 ≤ ƒ ≤ 70.
The effect of pulsating frequency on the local time
average Nusselt number at fixed Reynolds number of
16.8×103
is shown in Fig. 5. It can be seen that, as the
axial location moves downstream, the time average
local Nusselt number for both pulsating and steady
flows decays rapidly from a very large value near the
entrance and the axial decrease becomes less step in the
bulk of the pipe soon after leaving this entrance region.
The variation of the time averaged local Nusselt number
for pulsating turbulent air flow exhibits a similar trend
to that of the steady air flow case, but generally with
lower values than that of the steady flow for f < 61.13.
The maximum reduction of about 6% in the local
Nusselt number was predicted in the thermal entrance
region. For f ≥ 61.13, little enhancement in the local
time average Nusselt number of about 8% for X/D ≥ 50
was detected.
Figure 6 illustrates the variation of the ratio of the local
Nusselt number value for pulsating flow to that of the
steady flow value; η with the axial distance at Re =
22.5×103
. For f ≤ 39.3 Hz, it can be observed from Fig.
6-a that the ratio η starts rising rapidly in the entrance
zone of the thermally developed region (X/D<20) and
becomes nearly fixed below unity where its value in the
bulk of the pipe soon after leaving the entrance length
(X/D≥20) implies that the effect of pulsation on the
local heat transfer diminishes.
For f ≥ 42.5 Hz, the value of η close to the end of the
pipe enhanced by about 4%as shown in Fig. 6-b.
The impacts of other relevant parameters on heat
transfer are illustrated in Fig.7 (a, b). The detected
values of η due to the variation of pulsation frequency at
higher value of Reynolds number (Re = 31.6×10 3
). At
lower frequency (ƒ ≤ 39.3 Hz), a small change in heat
transfer ratio is visible near the entrance region. At
(ƒ=13.3 Hz) a rapid increases in η can be observed up to
X/D =20, after which it seems to be unchanged and
generally, the value of η is lees than unity. The same
trends can be seen for ƒ =28.3 Hz and ƒ =39.3 Hz.
However, in the downstream region the value of η
reaches about unity.
Velocity
Inlet
Axisymmetric
Adiabatic section Heated section
X
R
Outlet
Flow
Fig.3 Computational grid for pipe
5. Numerical study of heat transfer in pulsating turbulent air flow, E. A.M.Elshafei et al.
ThETA01/068 67
Fig.4. Variation of local Nusselt number at different
Reynolds number
The effect of changing pulsation frequency on the ratio
η seems to be negligible specially, for higher values of
pulsation frequency as can be noticed in Fig. 7.b.
At high values of Reynolds number; Re ≥ 37×103
,
certain qualitative trends can be shown in Figs. 8(a, b),
which are similar to those described in the previous
figures. For all studied values of pulsation frequency,
the values of the ratio η are always less than unity.
This global behavior of pulsating flow is consistent with
the analytical and numerical results of [5, 8, 20, 24, 29,
30 and 31]. The overall patterns of η curves are
qualitatively similar as discussed earlier.
Fig.6.Distrbution of η at different frequency, Re=22500
Fig.7.Distrbution of ηx at different frequency, Re=31600
X/D
Nux
0 20 40 60
0
100
200
300
400
Numerical Re=22500
Numerical Re=31600
Expermental Re=22500
Expermental Re=31600
η
η
0 20 40 60
0.84
0.88
0.92
0.96
1
1.04
Re=22500
f=6.67
f=13.3
f=20.3
f=28.3
f=39.3
0 20 40 60 80
0.88
0.92
0.96
1
1.04
1.08
RE=22500
f=42.5
f=45.7
f=53.13
f=61.13
f=68
X/D
X/D
(b)
(a)
Nux
Fig.5.Distrbution of Nux at different frequency, Re=16800
X/D
0 20 40 60
0
50
100
150
200
250
300
Re=16800
steady
f=42.5
f=45.7
f=49.13
f=53.13
f=61.13
f=68
0 20 40 60
0
50
100
150
200
250
300
Re=16800
steady
f=6.67
f=13.3
f=20.3
f=39.3
Nux
X/D
(b)
(a)
0 20 40 60
0.92
0.94
0.96
0.98
1
1.02
Re=31600
f=13.3
f=28.3
f=39.3
0 20 40 60
0.94
0.96
0.98
1
Re=31600
f=42.5
f=45.7
f=53.13
X/D
X/D
η
η
(b)
(a)
6. Numerical study of heat transfer in pulsating turbulent air flow, E. A.M.Elshafei et al.
ThETA01/06868
Fig.8. Distribution of η at different frequency, Re=37000
Fig.9. Heat transfer ratio for different Reynolds
Number and pulsation frequency.
The third set of results pertains to the effect of the
Reynolds number on the relative mean time- averaged
Nusselt; ηm in case of pulsating flow in pipes. The
calculated data for ηm versus Re are described in Figs.9
(a, b). In the range of pulsating frequency; ƒ ≤ 39.3, it
is found that Reynolds number strongly affects the heat
transfer ratio; ηm when Reynolds number is relatively
low; Re < 25 x 103
as can be noticed in Fig. 9-a. The
heat transfer ratio is sharply increases with Reynolds
number up to nearly unity. However, when Reynolds
number exceeds this value, the effect of increasing
Reynolds number diminishes and the value of ηm
remains nearly constant. It is also noticed that the
variation of the imposed pulsating frequency has a
relatively small effect on ηm. These computed results are
in consistent with that reported by Xuefeng. W. and
Nengli Z. [2]
Fig.10. Comparison of the experimental data
with numerical data at different (ω*)
For higher pulsation frequency; ƒ ≥ 42.5, the value of
the ratio ηm increases also with the increase of Reynolds
number. As ηm reaches to its peak value at Re ≈ 22.5 x
103
, it then smoothly decreases with increasing
Reynolds number up to 33 x 103
where ηm value is held
nearly constant for higher values of Reynolds number as
can be noticed in Fig. 9-b.
The behavior of Nusselt number corresponding to the
variation in both Reynolds number and pulsation
frequency can also be explained in view of the bursting
phenomena (Loiao and Wang [25] and Genin et al.
[26]). The bursting model defines certain regions on
frequency-Reynolds number plane, where, the bursting
frequency can be dependent or independent of the
pulsation frequency.
The present results showed that the heat transfer
coefficient may be increased or decreased with the
change of both Reynolds number and frequency. The
mean bursting frequency may be subdued to the
pulsation frequency leading to the occurring of
resonance that is dependent only on the pulsation
0 20 40 60
0.94
0.96
0.98
1
Re=37000
f=6.67
f=13.3
f=20.3
f=28.3
f=39.3
0 20 40 60
0.92
0.94
0.96
0.98
1
Re=37000
f=42.5
f=45.7
f=53.13
f=61.13
X/D
X/D
η
η
(b)
(a)
15000 20000 25000 30000 35000 40000
0.84
0.88
0.92
0.96
1
f=6.67
f=13.3
f=20.7
f=39.3
Re
(a)
ηm
Re
(b)
ηm
15000 20000 25000 30000 35000 40000
0.88
0.92
0.96
1
1.04
f=42.5
f=45.7
f=53.13
f=61.13
f=68
ω*
ω*
ηm
(a)
ω*
ηm
(b)
ηm
(c)
0 1 2 3
0.8
0.9
1
1.1
1.2
Re=37000
Experimental
Numerical
0 2 4 6
0.8
0.9
1
1.1
1.2
Re=16800
Experimental
Numerical
0 1 2 3 4 5
0.8
0.9
1
1.1
1.2
Re=22500
Experimental
Numerical
7. Numerical study of heat transfer in pulsating turbulent air flow, E. A.M.Elshafei et al.
ThETA01/068 69
frequency. Accordingly, the heat transfer process is
expected to be affected resulting in either reduction or
enhancement in the rate of heat transfer. These results
are in consistent with those reported by Habibi et al [17]
and Liao and Wang [25].
A comparison between the present numerical results
with the experimental ones [32] over a ranges of 16 x
103
< Re< 38x103
and 6.67 ≤ ƒ ≤ 68 Hz are described in
Fig. 10. The data are presented in the form of ηm as a
function of bursting frequency ω*
. It can be observed
that for all values of Reynolds number, the numerical
predictions of ηm as a function of ω*
have the sametrend
as those for the experimental data. The discrepancies
between the experimental data and the computed ones at
low bursting turbulent frequency are of about 10%. As
ω*
increases, the computed results closes to the
experimental ones, specially, at higher value of
Reynolds number.
In summary, the present elaborated numerical results for
heat transfer characteristics of turbulent pulsating flow
are useful. It can serve as a source of materials against
which further analytical data may be checked for
consistency.
5-CONCLUSTION
Simulation was performed to describe heat transfer in
pulsating turbulent air flow in a pipe using CFD code.
The simulation results on the fully developed pulsating
turbulent flow and heat transfer are compared with the
available experimental data. The findings suggest that
the heat transfer augmentation in the established flow
regions takes place only for a certain band of
frequencies. For extreme low and high frequencies, heat
transfer is actually reduced below that of steady flow.
The following may be concluded:
At all values of pulsation frequency, the
variations in the local time-averaged Nusselt
number exhibit similar trends to the steady
flows.
The local time-averaged Nusselt number either
increases or decreases than steady flow values
depending on the frequency and Reynolds
number.
Frequency has little effect on the values of
mean time-averaged Nusselt number especially
at higher values of pulsation frequency.
The presence of any pulsation frequency has a
noticed effect on the heat transfer coefficient in
comparison with that of steady flow, even at a
very small value of pulsation frequency.
However, the change of the value of pulsation
frequency has relativity small effect on the heat
transfer rates.
No increase in the mean time averaged-Nusselt
number for frequency f ≤39.34. For f ≥ 42.5,
little increase in time averaged-Nusselt number
is detected at Re ≈ 22.5x103
Nomenclature
Cp specific heat at constant pressure
, (J/Kg K)
C1, C2, Cµ empirical constant of k-ε model.
D diameter of pipe (m)
G the production of turbulent kinetic
energy (Kg/m s3
)
h instantaneous local heat transfer
coefficient, (W/m2
K)
ht instantaneous heat transfer coefficient
which is the average of heat transfer
coefficient over the whole length of
pipe at given moment, (W/m2
K)
hx local heat transfer coefficient which is
the average of heat transfer coefficient
over a cycle, (W/m2
k)
P pressure (pa)
K thermal conductivity, (W/m K)
k turbulent kinetic energy, (m2
/s2
)
L length of pipe, (m)
Nu overall Nusselt number
Nu t instantaneous Nusselt number
Nu x local Nusselt number
Pr Prandtl number, υ/α
q" heat flux per unit area(W/m2
)
r radial coordinate, (m)
R radius of pipe, (m)
Re Reynolds number, UD/υ
Tav average bulk temperature along cross-
sectional area of the pipe, (o
C)
Tin inlet temperature of the pipe (o
C)
Uin average of mean velocity at x=0, (m/s)
Uin =Um+ UA
Um Mean velocity of pulsating
component, (m/s)
UA Amplitude velocity of pulsating
component, (m/s)
UDF user defied function
u velocity component in the axial
direction (m/s)
v velocity component in the radial
direction (m/s)
x axial distance(m)
t time(s)
Greek symbols
α thermal diffusivity of fluid K/ρCp
(m2
/s)
ε turbulent energy dissipation rate
(W/kg)
φ viscous dissipation
µ dynamic viscosity (kg/m s)
µt eddy (or turbulent) viscosity (kg/m s)
υ kinematics viscosity (m2
/s)
ρ density (Kg/m3
)
σk turbulent Prandtl number for k
σT turbulent Prandtl number for T
8. Numerical study of heat transfer in pulsating turbulent air flow, E. A.M.Elshafei et al.
ThETA01/06870
σε turbulent Prandtl number for ε
ω angular frequency (1/s)
ω* dimensionless frequency; (ω
D/U*
), U* is the fraction velocity
described as U* =0.199Um /Re-0.125
η Relative local Nusselt number =
(Nupx/Nusx)
Subscripts
s Steady state
p pulsation
m mean
REFERENCES
[1] J.Zheng, D. Zeng, W. Ping, G. Hong, 2004, ‘’An
Experimental Study of Heat Transfer Enhancement With
Pulsating Flow’’, Heat transfer-Asian research, Vol,
23(5), pp. 279- 286
[2] W.Xuefeng, Z.Nengli, 2005 “Numerical Analysis of Heat
Transfer in Pulsating Turbulent Flow in a Pipe’’, J Heat
Mass Transfer, Vol,. 48, pp.3957-3970.
[3] Faghri. M, Javdani. K, Faghri. A, 1979 “Heat Transfer
with Laminar Pulsating Flow in Pipe’’. Lett Heat Mass
Transfer, Vol, 6(4), pp. 259–270
[4] Hesham M. Mostafa, A. M. Torki,K. M .Abd-Elsalam ,
2005 “Experimental Study for Forced Convection Heat
Transfer of Pulsating Flow Inside Horizontal
Tube’’.4th
International Conference on Heat Transfer,
Fluid Mechanics and Thermodynamics,Cario,Ak3,
[5] Hesham M. Mostafa, A. M. Torki,K. M .Abd-Elsalam,
2005, “Theoretical study of laminar pulsating flow in
pipe’’4thInternational Conference on Heat Transfer
,Fluid Mechanics and Thermodynamics,Cario.
[6] Hemeada, H. N, Sabry, M. N. AbdelRahim. A. Mansour
H, 2002, “Theoretical analysis of heat transfer in laminar
pulsating Flow’’, J Heat Mass Transfer, Vol, 45, pp.
1767-1780.
[7] Guo, Z. and Sung, H.j, 1997,”Analysis of the Nusselt
Number in pulsating Pipe Flow’’, J Heat Mass Transfer,
Vol, 40(10), pp .2486-2489.
[8] H.Chattopadhyay, F.Durst, S.Ray, 2006, “Analysis of
heat transfer in simultaneously developing pulsating
laminar flow in a pipe with constant wall temperature’’, J
Heat Mass Transfer, Vol, 33, pp. 475-481.
[9] Al-Haddad A, Al-Binally N, 1989, “Prediction of Heat
Transfer Coefficient in Pulsating Flow’’. Int J Heat Fluid
Flow, Vol, 10(2), pp. 131–133.
[10] T. S. Zhao and P. Cheng, 1998, “Heat Transfer in
Oscillatory Flows’’. Annual Review of Heat Transfer,
Vol, IX, chapter 7, pp. 1-64.
[11] Habib M.A, Said S.A.M, Al-Dini S.A, Asghar A,
Gbadebo S.A, 1999 ,”Heat transfer characteristics of
pulsated turbulent pipe flow’’. J Heat Mass Transfer, Vol,
34(5), pp.413–421.
[12] S.K.Gupa,R. D. Patel, R. C. Ackerberg, 1982, “ Wall
heat /Mass Transfer in pulsating Flow’’, chemical
Engineering Science, Vol, 37(12), pp.1727-173
[13] M. H. I. Barid, G. J. Duncan, J. I. Smith, J. Taylor, 1996,
“Heat Transfer in pulsed Turbulent Flow’’, chemical
Engineering Science, Vol,. 21, pp. 197-199.
[14] S. A. Gbadebo, S.A.M. Said, SAM, M.A. Habbib, 1999,
“ Average Nusselt number correlation in the thermal
entrance region of steady and pulsating turbulent pipe
flows’’. J Heat Mass Transfer, Vol, 35, pp.377–381.
[15] A. E. Zohir.M. M.A. Habbi. A. M. Attya. A.l. Eid, 2005,
“An Experimental Investigation of Heat Transfer to
Pulsating Pipe Air Flow with Different Amplitudes’’. J
Heat Mass Transfer, Vol, 42 (7), pp. 625-635.
[16] O.k.Erdal, J. L. Gainer, 1979, “The effect of pulsation on
heat transfer’’ ,Int. Eng. Chem. Fundam, Vol,. 18(10), pp.
11-15.
[17] M.A. Habbib, A.M. Attya, S.A.M. Said, A.l. Eid, A.Z.
Aly,2004, “Heat transfer characteristics and Nusselt
number correlation of turbulent pulsating air flows’’. J
Heat Mass Transfer, Vol,. 40, pp. 307-318.
[18] M.A. Habbib, A.M. Attya, S.A.M. Said, A.l. Eid, and
A.Z. Ally, 2002, “convective Heat transfer characteristics
of laminar pulsating air flow’’. J Heat Mass Transfer,
Vol,. 38, pp. 221-232.
[19] H. W. Cho and J. M. Hyun, 1990, “Numerical solutions
of pulsating flow and heat transfer characteristics in a
pipe’’ ,Int. J. Heat and fluid flow, Vol,.11,(4), pp. 321-
330.
[20] D,Y.Lee,S.J.Park,S.T.Ro, 1998, “ Heat transfer in the
thermally region of a laminar oscillating pipe flow’’
Ctyogenics, Vol,. 38, pp. 585-594.
[21] Moschandreou, T and Zamir, 1997, “ Heat transfer in a
tube with pulsating flow and constant heat flux’’, J Heat
Mass Transfer. Vol,. 35(10), pp. 2461-2466.
[22] A.Scotti,U.Piomelli, 2001, “ Numerical simulation of
pulsating turbulent channel flow’’, Physics of fluid,
Vol,.13(5), pp. 1367-1384.
[23] S.A.M.Said,M.A.Habib,M,O,Iqal, 2003, “Heat transfer to
pulsating flow in an abrupt pipe
expansion’’,Int,J,Num.Heat,Fluidflow, Vol,. 13(3), pp.
286,308.
[24] Lev.shemer, 1985, “Laminar-turbulent transition in a
slowly pulsating pipe flow’’,Phys.Fluids, Vol,. 28(12),
pp. 3506-3509.
[25] Liao Ns, Wang CC, 1985, “An investigation of the heat
transfer in pulsating turbulent pipe flow’’. Fundamentals
of forced and Mixed Convection. The 23th Nat Heat
Transfer Conf Denver.Co.U.S.A. Aug. 4-7,53-59.
[26] GeninLg, KovalAp, ManachkhaSp, SviridovVG, 1992,
“Hydrodynamics and heat transfer with pulsating fluid
flow in tubes’’. Thermal Eng Vol,.39950, pp. 30-34.
[27] Havemann, H, A and Rao, N,N, 1954, “heat transfer in
pulsating flow’’.Nature , Vol,. 7(4418), pp. 41.
[28] M.artineelli R.C;Boeleter LMK;Weinberg Eb;Yakahi S,
1943, “Heat transfer to a fluid flowing periodical at low
frequencies in a vertical tube’’. Trans. ASME Oct, pp.
789-798.
[29] S. Y. Kim, B. H. Kang, J. M. Hyun, 1993, “Heat Transfer
in The thermally Developed Region of a Pulsating
Channel Flow”, J Heat Mass Transfer, Vol,. 36 (17), pp.
4257-4266.
[30] Jie-Chang Yu,Zhi-Xin Li, T. s. Zhaoan , 2004,
“analytical study of pulsating laminar heat convection in
a circular tube with constant heat flux'', J Heat Mass
Transfer, Vol,. 47, pp. 5297-5301.
[31]E. A.M.Elshafei, M. Safwat.Mohamed, H. Mansour;
M.Sakr, 2006, “Experimental Study of Heat Transfer in
Pulsating Turbulent Flow in a Pipe”, publications in
process (8th
International Congress of Fluid Dynamics &
Propulsion, 2006.
[32] Y.HÜSEYİN, B. GAMZE, K. NESRİN and Y. ŞENAY,
2005, “Numerical Study on Transient Local Entropy
Generation in Pulsating Turbulent Flow through an
Externally Hated Pipe” Sădhană, Vol. 30, Part 5, October
2005, pp. 625–648.