Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2020
The objective of this work is the mathematical modelling and the numerical simulation of the stat... more The objective of this work is the mathematical modelling and the numerical simulation of the stationary, laminar, and natural convection, in a confined square cavity (H = L) filled with two fluids (a mixture of nanoparticles of aluminum oxide and Al2O3 water) in one partition and pure water in the other partition. A porous conductive wall of thickness w (w = L/e) and thermal conductivity Keff constitutes the exchange surface between these two partitions. The fluid movement is modeled by the Navier-Stokes equations in the two partitions, while the porous medium is modelled by the Darcy–Brinkman equation. Comsol Multiphysics software is used to solve the system of differential equations that is based on the finite element method. The results are discussed with particular attention to the mean and local Nusselt number (Nu), streamlines and isotherms. A parametric study for Rayleigh number Ra (102 to 106), volume fraction j (0% to 10%), and Darcy number Da (10-7 to 10-2) is performed. T...
International Journal of Heat and Technology, 2020
The present paper is focused on the study of natural convection in a porous square cavity saturat... more The present paper is focused on the study of natural convection in a porous square cavity saturated by a nanofluid (Al2O3-Water) in the presence of a corrugated heat source. The horizontal walls and the hatched parts of the vertical walls are considered adiabatic. The corrugated portions of the vertical walls are maintained at uniform and constant temperatures. The basic equations describing the natural convection flow consist of mass conservation, Darcy-Brinkman and energy were solved by means of finite element method. For the physical parameters of (Al2O3-water) nanofluid, we use the Brinkman and Maxwell models. The results are presented as isotherms, streamlines, average Nusselt number, velocity and temperature profiles for various combinations of Modified Rayleigh number, volume fraction of nanoparticles, amplitude and both sources position. It is found that the heat transfer increases with the increase of Modified Rayleigh number, volume fraction and amplitude. The hot source is at the bottom and the cold source is at the top is the optimal position of the two sources to evacuate better the convection heat transfer.
Buildings are complex systems composed of several elements, which are assembled to respond to a n... more Buildings are complex systems composed of several elements, which are assembled to respond to a number of needs functional and symbolic according to set of legal and environmental requirements and potentially accommodate users with different levels of demand. Predicting the conception of the external wall is beneficial in the design of house and building structures.in this study, an analogy was used for the functions which are discretized by the finite difference method and integrated in the CFD code which is based on the finite volume method. The CFD software is used as a technique to modelling the behaviour of fluid and the thermal convection in the external wall of the house with different Rayleigh numbers [10 3 Ra 10 5 ]. In the second phase, we change the thickness of the wall several times and calculate the Nusselt number and exchange coefficient of heat transfer aims to find a cloud point respectively for the thicknesses e = 0, L /40, L /20 and L /10. After, we developed a relationship that helps us to know the exchange ratio for each thickness (e) belongs to the interval [0, L /10] by the Lagrange polynomial interpolation method for Rayleigh number equal 10 4 , and then we developed a FORTRAN program to control the nonlinear equation of order three. This method for predicting exchange coefficient of convection for to optimize the design of walls in buildings.
International Journal of Natural Sciences Research, 2015
This research work attempts to present an experimental study on the structure of the former labor... more This research work attempts to present an experimental study on the structure of the former laboratory of vibration and structural dynamics in the technological hall that belong to Bechar University. This study tries to determinate the real behavior of this structure. The structure is exited by background noise generated by a vibrating table compacting concrete, placed inside the laboratory, after we simulate this noise with an electrodynamics shaker. The response of the structure was captured by a tri-axial accelerometer. The experimental results are presented under an auto spectrum, for determining the eigenfrequencies of the structure, this values are compared with those obtund from a numerical simulation bases on the finite elements method.
In the proposed study, an investigation has been carried out in order to find a material efficien... more In the proposed study, an investigation has been carried out in order to find a material efficient structure, capable of harnessing maximum solar spectrum. A material efficient structure designed using a one dimensional photonic crystal (1D PC) for amorphous silicon. Silicon material is used as it leads to environmental friendly design. The principal objective of this study is to maximize the photon absorption, keeping reflection to a minimum. The influence of geometric parameters on the absorption is studied by using the Finite element method (FEM). The results show that the absorption is affected by the geometry parameters. The optimum parameters of the proposed structure are period (a 480 nm), a filling factor (ff 50 %) and depth (d 150 nm). The increase of absorption in the lower region where the wavelengths are around 480 nm, is explained by the reduction of the effective index resulting from the structure of the absorbent layer. For wavelengths between 480 nm and 600 nm, the absorption is directly related to existing Fabry-Perot modes within the absorbent layer. Creating additional absorption peaks at wavelengths above about 600 nm weakly absorbed normally comes from the coupling of the incident light with slow Bloch modes of PC located above the light line.
The objective of this work is to study the thermal conductivity ratio (kr) effect on the structur... more The objective of this work is to study the thermal conductivity ratio (kr) effect on the structure of natural convection flow in a partially porous cavity. A cylindrical heat source maintained at a uniform temperature is introduced into a porous portion. The equations which describe the thermal transfer and the hydrodynamic flow are described by the Navier-Stokes equations modified by the extension of Darcy-Brinkman model and the energy equation. The results obtained are in the form of isotherm distribution, streamlines, the average Nusselt numbers and pressure. Correlations between these parameters and the thermal conductivity ratio are considered. This study is the one application object to the creation of a climate favorable to pushed plants in an agricultural greenhouse in an arid region.
In this paper, we study by numerical simulation natural convection of Al 2 O 3-water nanofluid in... more In this paper, we study by numerical simulation natural convection of Al 2 O 3-water nanofluid in square cavity. In this cavity, the horizontal walls are isothermal, maintained at cold (T c) and hot (T h) temperatures. The vertical walls are adiabatic. A vertical magnetic field is externally imposed. The basic equations describing the flow driven by natural convection consist of mass conservation, momentum and energy. These equations are solved numerically by finite element method. A numerical simulation of the problem was performed using the software Comsol Multiphysics. For the physical parameters of Al 2 O 3 +water nanofluid, we use the Brinkman and Wasp model. Numerical results are presented for wide range of Hartmann number (Ha=0 to 100), with a value of Grashof number Gr=10 4 and volume fraction ϕ=0.1 in terms of streamlines, isotherms and the flux ratio. The results show that the magnetic field has effects on the flow and heat transfer.
Two-dimensional, double diffusion, natural convection in a partially porous cavity satured with a... more Two-dimensional, double diffusion, natural convection in a partially porous cavity satured with a binary fluid is investigated numerically. Multiple motions are driven by the external temperature and concentration differences imposed across vertical walls. The wavy interface between fluid and porous layer is horizontal. The equations which describe the fluid flow and heat and mass transfer are described by the Navier-Stokes equations (fluid region), Darcy-Brinkman equation (porous region) and energy and mass equations. The finite element method was applied to solve the governing equations. The fluid flow and heat and mass transfer has been investigated for different values of the amplitude and the wave number of the interface and the buoyancy ratio. The results obtained in the form of isotherms, stream lines, isoconcentrations and the Nusselt and Sherwood numbers; show that the wavy interface has a significant effect on the flow and heat and mass transfer.
The objective of this study is the comparison between the model of Darcy-Brinkman and the Navier-... more The objective of this study is the comparison between the model of Darcy-Brinkman and the Navier-Stokes equations modified, in the case of the natural convection. The study is made in a porous vertical square cavity saturated by a Newtonian fluid. A cylindrical heat source maintained at a uniform heat flux is introduced into porous medium. The equations which describe the thermal transfer and the hydrodynamic flow of the two models are solved numerically by means of the software package Femlab 3.2 based on the finite element method. The results obtained are in the form of average kinetic energy per unit mass, the local and the average Nusselt numbers, the pressure and the viscous force per unit area.
In this paper we study by numerical simulation, the cooling of a solar cell by forced convection ... more In this paper we study by numerical simulation, the cooling of a solar cell by forced convection in the presence of a nanofluid. The inclined walls of the cavity are adiabatic but the silicon solar cells are subjected to a constant heat temperature. The nanofluid is introduced into the cavity with a constant vertical speed and subjected to room temperature. The equations governing the flow hydrodynamics and heat transfer are described by the Navier-Stockes and energy equations. For the physical parameters of Al 2 O 3-Water nanofluid, we use the model of Brinkman and Wasp. The finite elements method is used to solve the system of differential equations that is based on the Galerkin method. We consider the effect of solid volume fraction for different values of Reynolds number on the results in the form of isotherms and modified local and average Nusselt number.
The International Journal of Multiphysics, Dec 31, 2019
Due to the significant increase in temperature in summer in the Saharan zone in this case the tow... more Due to the significant increase in temperature in summer in the Saharan zone in this case the town of Bechar, electric power medium voltage to low voltage substations (MV / LV) installed by companies distribution of electricity and gas (SONELGAZ) undergo additional constraints compared to those installed in the north, due to overheating which reduces the life of the plant and cause adverse judgments to clients. In this context, the work presented a numerical study the type post of public distribution, has content a transformer and taking into account the measures taken by the outdoor temperature weather station lab ENERGARID. The objective of this study is to analyze the results of the distribution of temperature, aeration and streamline to the inside of the post.
The proposed work studies numerically the mixed convection heat transfer in a station electric tr... more The proposed work studies numerically the mixed convection heat transfer in a station electric transformer MV / LV for the public distribution of a neighborhood located in the town of Bechar (Sahara region) in the southwest Algeria. Taking into account the climatic conditions measured during the summer period [1], introduced as boundary conditions using the Fluent CFD based on the finite volume method. In order to get results presented in form the isothermal and the stream function and the profile of the evolution of the temperature and velocity components of the air inside the station.The objective of this study is to analyze the results of the distribution of temperature, aeration of the position and the flow of air to the interior of the station.The influence of the number and location of openings in the station is studied.
This study focuses on the numerical simulation of heat transfer by natural convection in a rectan... more This study focuses on the numerical simulation of heat transfer by natural convection in a rectangular enclosure, filled with a liquid metal (low Prandtl number) partially heated from below with a sinusoidal temperature. The value of the study lies in its involvement in the crystal growth for the manufacture of semiconductors and electronics cooling. Indeed, the occurrence of convection during crystal growth can lead to in homogeneities that lead to striations and defects that affect the quality of the crystals obtained by the Bridgman techniques or Chochrawlski. Temperature of the oscillations, due to the instabilities of the convective flow in the liquid metal, also induces non-uniform cooling in the solidification front. Convection is then studied in order to reduce it. A modelling of the problem in two dimensions was conducted using Comsol computer code that is based on the finite element method, by varying the configuration of the control parameters, namely, the Rayleigh number, the nature of fluid (Prandtl number) and amplitude of temperature on heat transfer rate (Nusselt number) on convective structures that appear. This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits distribution, and reproduction in any medium, provided the original work is properly cited.
The International Journal of Multiphysics, Dec 31, 2016
This study deals with the transient heat transfer in a multi-layered building wall through the fa... more This study deals with the transient heat transfer in a multi-layered building wall through the facades of the buildings located in the city of Bechar (southwest Algeria). The physical model is presented to find the variation of the transient temperature in these structures and the heat flux through these elements, which depends on the air temperature of the inner surface and the instantaneous climatic conditions of the air outside. Comsol Multiphysics based on the finite element method is designed to perform numerical simulations. The measured hourly ambient air temperatures and the solar radiation flux on the horizontal surface for the city of Bechar Algeria are using during the hottest period (July 2015), and also using the properties Thermodynamics of each component of the structure. The validation of the analytical model with this simulation is verified in this document. The calculations carried out for different multilayer building walls which are commonly used in the south of Algeria to determine the thermal behavior of these structures and the influence of radiation heat flux on these elements.
This work presents a study by numerical simulation of mixed convection in a rectangular cavity wi... more This work presents a study by numerical simulation of mixed convection in a rectangular cavity with a sinusoidal temperature imposed on the right vertical wall while the other wall on the left is kept at a cold temperature. The upper and lower walls are thermally insulated, the inlet and outlet ports are respectively located on the hot wall to the bottom and on the top to the left. The enclosure represents a practical system such as an air-cooled electronic device, the heat source represents a radiator or an electronic component located in three different positions towards the left side at the bottom, the center and towards the right side at the top in such an enclosure. All calculations are made for a range of Richardson number from 0 to 10 and Reynolds numbers from 50 to 200. The influence of Richardson number, the position of the heat source and the influence of amplitude and phase deviation of the temperature imposed on the Nusselt number on the hot surface is studied. The resul...
WSEAS TRANSACTIONS ON HEAT AND MASS TRANSFER, 2021
The present investigation deals with the natural, mixed and forced convection in a vented rectang... more The present investigation deals with the natural, mixed and forced convection in a vented rectangular cavity having a sinusoidal heated vertical wall with a conducting solid block placed at one of the nine positions. The objective is to analyze numerically using finite element method the effects of the following parameters: inlet, outlet positions, solid square positions, thermal coefficient λ, amplitude ratio ɛ, phase deviation ϕ and the solid square size on the thermo-convective flows. The Richardson number is varied from 0 to 40, the Reynolds and Prandtl numbers are fixed respectively at 100 and 0.71. To quantify the heat transfer of the solid block and to get closer to real conditions, we have developed a modification based on the evaluation of the Nusselt number using the average temperature in the cavity, unlike previous works which used the input temperature. As results, the sinusoidal temperature at the right wall gives higher heat transfer enhancement. The variation of the ...
Proceeding of Proceedings of CHT-15. 6th International Symposium on ADVANCES IN COMPUTATIONAL HEAT TRANSFER , May 25-29, 2015, Rutgers University, New Brunswick, NJ, USA, 2015
Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2020
The objective of this work is the mathematical modelling and the numerical simulation of the stat... more The objective of this work is the mathematical modelling and the numerical simulation of the stationary, laminar, and natural convection, in a confined square cavity (H = L) filled with two fluids (a mixture of nanoparticles of aluminum oxide and Al2O3 water) in one partition and pure water in the other partition. A porous conductive wall of thickness w (w = L/e) and thermal conductivity Keff constitutes the exchange surface between these two partitions. The fluid movement is modeled by the Navier-Stokes equations in the two partitions, while the porous medium is modelled by the Darcy–Brinkman equation. Comsol Multiphysics software is used to solve the system of differential equations that is based on the finite element method. The results are discussed with particular attention to the mean and local Nusselt number (Nu), streamlines and isotherms. A parametric study for Rayleigh number Ra (102 to 106), volume fraction j (0% to 10%), and Darcy number Da (10-7 to 10-2) is performed. T...
International Journal of Heat and Technology, 2020
The present paper is focused on the study of natural convection in a porous square cavity saturat... more The present paper is focused on the study of natural convection in a porous square cavity saturated by a nanofluid (Al2O3-Water) in the presence of a corrugated heat source. The horizontal walls and the hatched parts of the vertical walls are considered adiabatic. The corrugated portions of the vertical walls are maintained at uniform and constant temperatures. The basic equations describing the natural convection flow consist of mass conservation, Darcy-Brinkman and energy were solved by means of finite element method. For the physical parameters of (Al2O3-water) nanofluid, we use the Brinkman and Maxwell models. The results are presented as isotherms, streamlines, average Nusselt number, velocity and temperature profiles for various combinations of Modified Rayleigh number, volume fraction of nanoparticles, amplitude and both sources position. It is found that the heat transfer increases with the increase of Modified Rayleigh number, volume fraction and amplitude. The hot source is at the bottom and the cold source is at the top is the optimal position of the two sources to evacuate better the convection heat transfer.
Buildings are complex systems composed of several elements, which are assembled to respond to a n... more Buildings are complex systems composed of several elements, which are assembled to respond to a number of needs functional and symbolic according to set of legal and environmental requirements and potentially accommodate users with different levels of demand. Predicting the conception of the external wall is beneficial in the design of house and building structures.in this study, an analogy was used for the functions which are discretized by the finite difference method and integrated in the CFD code which is based on the finite volume method. The CFD software is used as a technique to modelling the behaviour of fluid and the thermal convection in the external wall of the house with different Rayleigh numbers [10 3 Ra 10 5 ]. In the second phase, we change the thickness of the wall several times and calculate the Nusselt number and exchange coefficient of heat transfer aims to find a cloud point respectively for the thicknesses e = 0, L /40, L /20 and L /10. After, we developed a relationship that helps us to know the exchange ratio for each thickness (e) belongs to the interval [0, L /10] by the Lagrange polynomial interpolation method for Rayleigh number equal 10 4 , and then we developed a FORTRAN program to control the nonlinear equation of order three. This method for predicting exchange coefficient of convection for to optimize the design of walls in buildings.
International Journal of Natural Sciences Research, 2015
This research work attempts to present an experimental study on the structure of the former labor... more This research work attempts to present an experimental study on the structure of the former laboratory of vibration and structural dynamics in the technological hall that belong to Bechar University. This study tries to determinate the real behavior of this structure. The structure is exited by background noise generated by a vibrating table compacting concrete, placed inside the laboratory, after we simulate this noise with an electrodynamics shaker. The response of the structure was captured by a tri-axial accelerometer. The experimental results are presented under an auto spectrum, for determining the eigenfrequencies of the structure, this values are compared with those obtund from a numerical simulation bases on the finite elements method.
In the proposed study, an investigation has been carried out in order to find a material efficien... more In the proposed study, an investigation has been carried out in order to find a material efficient structure, capable of harnessing maximum solar spectrum. A material efficient structure designed using a one dimensional photonic crystal (1D PC) for amorphous silicon. Silicon material is used as it leads to environmental friendly design. The principal objective of this study is to maximize the photon absorption, keeping reflection to a minimum. The influence of geometric parameters on the absorption is studied by using the Finite element method (FEM). The results show that the absorption is affected by the geometry parameters. The optimum parameters of the proposed structure are period (a 480 nm), a filling factor (ff 50 %) and depth (d 150 nm). The increase of absorption in the lower region where the wavelengths are around 480 nm, is explained by the reduction of the effective index resulting from the structure of the absorbent layer. For wavelengths between 480 nm and 600 nm, the absorption is directly related to existing Fabry-Perot modes within the absorbent layer. Creating additional absorption peaks at wavelengths above about 600 nm weakly absorbed normally comes from the coupling of the incident light with slow Bloch modes of PC located above the light line.
The objective of this work is to study the thermal conductivity ratio (kr) effect on the structur... more The objective of this work is to study the thermal conductivity ratio (kr) effect on the structure of natural convection flow in a partially porous cavity. A cylindrical heat source maintained at a uniform temperature is introduced into a porous portion. The equations which describe the thermal transfer and the hydrodynamic flow are described by the Navier-Stokes equations modified by the extension of Darcy-Brinkman model and the energy equation. The results obtained are in the form of isotherm distribution, streamlines, the average Nusselt numbers and pressure. Correlations between these parameters and the thermal conductivity ratio are considered. This study is the one application object to the creation of a climate favorable to pushed plants in an agricultural greenhouse in an arid region.
In this paper, we study by numerical simulation natural convection of Al 2 O 3-water nanofluid in... more In this paper, we study by numerical simulation natural convection of Al 2 O 3-water nanofluid in square cavity. In this cavity, the horizontal walls are isothermal, maintained at cold (T c) and hot (T h) temperatures. The vertical walls are adiabatic. A vertical magnetic field is externally imposed. The basic equations describing the flow driven by natural convection consist of mass conservation, momentum and energy. These equations are solved numerically by finite element method. A numerical simulation of the problem was performed using the software Comsol Multiphysics. For the physical parameters of Al 2 O 3 +water nanofluid, we use the Brinkman and Wasp model. Numerical results are presented for wide range of Hartmann number (Ha=0 to 100), with a value of Grashof number Gr=10 4 and volume fraction ϕ=0.1 in terms of streamlines, isotherms and the flux ratio. The results show that the magnetic field has effects on the flow and heat transfer.
Two-dimensional, double diffusion, natural convection in a partially porous cavity satured with a... more Two-dimensional, double diffusion, natural convection in a partially porous cavity satured with a binary fluid is investigated numerically. Multiple motions are driven by the external temperature and concentration differences imposed across vertical walls. The wavy interface between fluid and porous layer is horizontal. The equations which describe the fluid flow and heat and mass transfer are described by the Navier-Stokes equations (fluid region), Darcy-Brinkman equation (porous region) and energy and mass equations. The finite element method was applied to solve the governing equations. The fluid flow and heat and mass transfer has been investigated for different values of the amplitude and the wave number of the interface and the buoyancy ratio. The results obtained in the form of isotherms, stream lines, isoconcentrations and the Nusselt and Sherwood numbers; show that the wavy interface has a significant effect on the flow and heat and mass transfer.
The objective of this study is the comparison between the model of Darcy-Brinkman and the Navier-... more The objective of this study is the comparison between the model of Darcy-Brinkman and the Navier-Stokes equations modified, in the case of the natural convection. The study is made in a porous vertical square cavity saturated by a Newtonian fluid. A cylindrical heat source maintained at a uniform heat flux is introduced into porous medium. The equations which describe the thermal transfer and the hydrodynamic flow of the two models are solved numerically by means of the software package Femlab 3.2 based on the finite element method. The results obtained are in the form of average kinetic energy per unit mass, the local and the average Nusselt numbers, the pressure and the viscous force per unit area.
In this paper we study by numerical simulation, the cooling of a solar cell by forced convection ... more In this paper we study by numerical simulation, the cooling of a solar cell by forced convection in the presence of a nanofluid. The inclined walls of the cavity are adiabatic but the silicon solar cells are subjected to a constant heat temperature. The nanofluid is introduced into the cavity with a constant vertical speed and subjected to room temperature. The equations governing the flow hydrodynamics and heat transfer are described by the Navier-Stockes and energy equations. For the physical parameters of Al 2 O 3-Water nanofluid, we use the model of Brinkman and Wasp. The finite elements method is used to solve the system of differential equations that is based on the Galerkin method. We consider the effect of solid volume fraction for different values of Reynolds number on the results in the form of isotherms and modified local and average Nusselt number.
The International Journal of Multiphysics, Dec 31, 2019
Due to the significant increase in temperature in summer in the Saharan zone in this case the tow... more Due to the significant increase in temperature in summer in the Saharan zone in this case the town of Bechar, electric power medium voltage to low voltage substations (MV / LV) installed by companies distribution of electricity and gas (SONELGAZ) undergo additional constraints compared to those installed in the north, due to overheating which reduces the life of the plant and cause adverse judgments to clients. In this context, the work presented a numerical study the type post of public distribution, has content a transformer and taking into account the measures taken by the outdoor temperature weather station lab ENERGARID. The objective of this study is to analyze the results of the distribution of temperature, aeration and streamline to the inside of the post.
The proposed work studies numerically the mixed convection heat transfer in a station electric tr... more The proposed work studies numerically the mixed convection heat transfer in a station electric transformer MV / LV for the public distribution of a neighborhood located in the town of Bechar (Sahara region) in the southwest Algeria. Taking into account the climatic conditions measured during the summer period [1], introduced as boundary conditions using the Fluent CFD based on the finite volume method. In order to get results presented in form the isothermal and the stream function and the profile of the evolution of the temperature and velocity components of the air inside the station.The objective of this study is to analyze the results of the distribution of temperature, aeration of the position and the flow of air to the interior of the station.The influence of the number and location of openings in the station is studied.
This study focuses on the numerical simulation of heat transfer by natural convection in a rectan... more This study focuses on the numerical simulation of heat transfer by natural convection in a rectangular enclosure, filled with a liquid metal (low Prandtl number) partially heated from below with a sinusoidal temperature. The value of the study lies in its involvement in the crystal growth for the manufacture of semiconductors and electronics cooling. Indeed, the occurrence of convection during crystal growth can lead to in homogeneities that lead to striations and defects that affect the quality of the crystals obtained by the Bridgman techniques or Chochrawlski. Temperature of the oscillations, due to the instabilities of the convective flow in the liquid metal, also induces non-uniform cooling in the solidification front. Convection is then studied in order to reduce it. A modelling of the problem in two dimensions was conducted using Comsol computer code that is based on the finite element method, by varying the configuration of the control parameters, namely, the Rayleigh number, the nature of fluid (Prandtl number) and amplitude of temperature on heat transfer rate (Nusselt number) on convective structures that appear. This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits distribution, and reproduction in any medium, provided the original work is properly cited.
The International Journal of Multiphysics, Dec 31, 2016
This study deals with the transient heat transfer in a multi-layered building wall through the fa... more This study deals with the transient heat transfer in a multi-layered building wall through the facades of the buildings located in the city of Bechar (southwest Algeria). The physical model is presented to find the variation of the transient temperature in these structures and the heat flux through these elements, which depends on the air temperature of the inner surface and the instantaneous climatic conditions of the air outside. Comsol Multiphysics based on the finite element method is designed to perform numerical simulations. The measured hourly ambient air temperatures and the solar radiation flux on the horizontal surface for the city of Bechar Algeria are using during the hottest period (July 2015), and also using the properties Thermodynamics of each component of the structure. The validation of the analytical model with this simulation is verified in this document. The calculations carried out for different multilayer building walls which are commonly used in the south of Algeria to determine the thermal behavior of these structures and the influence of radiation heat flux on these elements.
This work presents a study by numerical simulation of mixed convection in a rectangular cavity wi... more This work presents a study by numerical simulation of mixed convection in a rectangular cavity with a sinusoidal temperature imposed on the right vertical wall while the other wall on the left is kept at a cold temperature. The upper and lower walls are thermally insulated, the inlet and outlet ports are respectively located on the hot wall to the bottom and on the top to the left. The enclosure represents a practical system such as an air-cooled electronic device, the heat source represents a radiator or an electronic component located in three different positions towards the left side at the bottom, the center and towards the right side at the top in such an enclosure. All calculations are made for a range of Richardson number from 0 to 10 and Reynolds numbers from 50 to 200. The influence of Richardson number, the position of the heat source and the influence of amplitude and phase deviation of the temperature imposed on the Nusselt number on the hot surface is studied. The resul...
WSEAS TRANSACTIONS ON HEAT AND MASS TRANSFER, 2021
The present investigation deals with the natural, mixed and forced convection in a vented rectang... more The present investigation deals with the natural, mixed and forced convection in a vented rectangular cavity having a sinusoidal heated vertical wall with a conducting solid block placed at one of the nine positions. The objective is to analyze numerically using finite element method the effects of the following parameters: inlet, outlet positions, solid square positions, thermal coefficient λ, amplitude ratio ɛ, phase deviation ϕ and the solid square size on the thermo-convective flows. The Richardson number is varied from 0 to 40, the Reynolds and Prandtl numbers are fixed respectively at 100 and 0.71. To quantify the heat transfer of the solid block and to get closer to real conditions, we have developed a modification based on the evaluation of the Nusselt number using the average temperature in the cavity, unlike previous works which used the input temperature. As results, the sinusoidal temperature at the right wall gives higher heat transfer enhancement. The variation of the ...
Proceeding of Proceedings of CHT-15. 6th International Symposium on ADVANCES IN COMPUTATIONAL HEAT TRANSFER , May 25-29, 2015, Rutgers University, New Brunswick, NJ, USA, 2015
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