In this paper, we study by numerical simulation, the cooling of a solar photovoltaic panel using ... more In this paper, we study by numerical simulation, the cooling of a solar photovoltaic panel using a nanofluid as a cooler. The solar panel is subjected to a hot temperature that character-ises the climate of the city of Bechar located in southwestern Algeria. The nanofluid (Al2O3-water) is introduced in the cavity with a constant horizontal speed and subjected to the ambient (cold) temperature. The equations governing the hydrodynamics of the flow and the heat transfer are described by the Navier-Stockes and energy equations. The finite element method is used to solve the system of partial differential equations (PDEs) based on the Galerkin method. We consider the effect of solid volume fraction and form factor for different values of Reynolds number on the results in the form of isotherms, streamlines, temperature, velocity, average Nusselt numbers and solar panel efficiency.
In this paper, the behavior of an elastic barrier subjected to isothermal laminar flow of Al2O3-w... more In this paper, the behavior of an elastic barrier subjected to isothermal laminar flow of Al2O3-water nanofluid in a channel has been studied numerically by the finite element method. A CFD based on the arbitrary Lagrange-Euler (ALE) formulation, has been developed in an attempt to solve the Navier-Stokes and stress-strain equations of the structure. The objective is to study the effects of inertia (Re) and nanoparticle volume fraction (φ) on the overall hydrodynamic behavior, as well as on the nanofluid-structure interface. The results showed that the deformation of the structure was mainly caused by the pressure loading of the nanofluid and the viscous drag imposed on the structure walls. In addition, the structure was strongly affected by the increase in Reynolds number and volume fraction of the nanoparticles. Finally, a numerical correlation was established to determine the maximum displacement caused by the bending of the structure.
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 ...
By running a nonlinear scan of a proper values analysis using the nonlinear solver with an additi... more By running a nonlinear scan of a proper values analysis using the nonlinear solver with an additional normalization equation for the proper value and 2D FEM simulations, we show the influence of some parameters such as the electric field; the magnetic field and the heating by joule effect of the photonic band gap structures 2D. The study is carried out in consideration of wave propagation in a photonic crystal composed of GaAs columns equidistant from one another. This model extracts the band diagram for the lowest frequencies of the crystal.
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...
Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2020
This study tested the effectiveness of some natural ventilation basic configurations for the ther... more This study tested the effectiveness of some natural ventilation basic configurations for the thermal comfort of occupants in different local climates in Algeria. Due to the diverse Algerian climate, the study was performed during the mid-season period that includes three months of May, September, and October and the summer that includes the months of June, July, and August. The ventilation potential of the selected configurations was analysed through numerical simulation by using TRNSYS software coupled with COMIS aeraulic software. The results showed the significant contribution of natural chimney ventilation caused by a stairwell to improve occupant comfort. However; its integration requires a judicious and permanent inspection to control temperature decreases or overheating risks.
International Journal of Heat and Technology, 2021
Received: 10 May 2020 Accepted: 16 December 2020 The purpose of research presented in this paper ... more Received: 10 May 2020 Accepted: 16 December 2020 The purpose of research presented in this paper is to study the thermal and hydrodynamic effect of the non-isothermal laminar flow of a Al2O3-water nanofluid having shear thinning behavior in a mechanically stirred tank using the finite element method. Numerical simulation has been performed for a non-stationary two-dimensional flow controlled by certain influencing parameters such as the Reynolds number (1 ≤ Re ≤ 200), the behavior index (0.6 ≤ n ≤ 1) and the volume fraction of the alumina nanoparticles (0 ≤ φ ≤ 0.1). The simulation results obtained show that the addition of the Al2O3 nanoparticles in the base fluid leads to a significant enhancement in the heat transfer in the stirred tank compared to the base fluid. On the other hand, we note a slight decrease in the heat transfer with the decrease in the behavior index. It has also been noted, that the agitation power increases relatively with the volume fraction of the Alumina na...
The objective of this study is the comparison between the model of DarcyBrinkman and the Navier-S... more The objective of this study is the comparison between the model of DarcyBrinkman 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.
The objective of the present work is to study the effect of horizontal vibratory excitation on th... more The objective of the present work is to study the effect of horizontal vibratory excitation on the behavior of a water-Al2O3 nanofluid in natural convection in a cavity. The nanofluid used is composed of aluminum oxide nanoparticles in suspension of water, is provided at various volume fractions. The two horizontal walls are isothermal, maintained at cold temperature Tc and heat temperature Th. The two vertical walls are adiabatic. The basic equations describing the flow driven by natural convection consist of mass conservation, momentum and energy. For the physical parameters of Al2O3+water nanofluid, we use the Brinkman and Wasp model. Transport equations are solved numerically by finite element method. Results are presented in the form of streamlines, isotherms and the flux ratio.
In this work, a numerical study has been performed for the problem of steady-state natural convec... more In this work, a numerical study has been performed for the problem of steady-state natural convection in a square porous cavity having a solid wall of finite thickness and conductivity filled by a nanofluid in the presence of two isothermal cylindrical sources. The external walls of the cavity are considered adiabatic and the circular sources are maintained at a hot and cold uniform temperatures. The internal thick wall has been a conducting solid. The governing dimensionless equations are solved using Galerkin finite element method and Darcy-Brinkman model assumed to be adopted. The results are presented as isotherms, streamlines, stream function values, average and local Nusselt number for various combinations of Rayleigh and Darcy numbers, concentration of nanoparticles, Thermal conductivity ratio, and dimensionless wall thickness of the solid portion. The convection heat transfer can be enhanced by increasing of these parameters except for the wall thickness.
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 this paper, we study by numerical simulation, the cooling of a solar photovoltaic panel using ... more In this paper, we study by numerical simulation, the cooling of a solar photovoltaic panel using a nanofluid as a cooler. The solar panel is subjected to a hot temperature that character-ises the climate of the city of Bechar located in southwestern Algeria. The nanofluid (Al2O3-water) is introduced in the cavity with a constant horizontal speed and subjected to the ambient (cold) temperature. The equations governing the hydrodynamics of the flow and the heat transfer are described by the Navier-Stockes and energy equations. The finite element method is used to solve the system of partial differential equations (PDEs) based on the Galerkin method. We consider the effect of solid volume fraction and form factor for different values of Reynolds number on the results in the form of isotherms, streamlines, temperature, velocity, average Nusselt numbers and solar panel efficiency.
In this paper, the behavior of an elastic barrier subjected to isothermal laminar flow of Al2O3-w... more In this paper, the behavior of an elastic barrier subjected to isothermal laminar flow of Al2O3-water nanofluid in a channel has been studied numerically by the finite element method. A CFD based on the arbitrary Lagrange-Euler (ALE) formulation, has been developed in an attempt to solve the Navier-Stokes and stress-strain equations of the structure. The objective is to study the effects of inertia (Re) and nanoparticle volume fraction (φ) on the overall hydrodynamic behavior, as well as on the nanofluid-structure interface. The results showed that the deformation of the structure was mainly caused by the pressure loading of the nanofluid and the viscous drag imposed on the structure walls. In addition, the structure was strongly affected by the increase in Reynolds number and volume fraction of the nanoparticles. Finally, a numerical correlation was established to determine the maximum displacement caused by the bending of the structure.
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 ...
By running a nonlinear scan of a proper values analysis using the nonlinear solver with an additi... more By running a nonlinear scan of a proper values analysis using the nonlinear solver with an additional normalization equation for the proper value and 2D FEM simulations, we show the influence of some parameters such as the electric field; the magnetic field and the heating by joule effect of the photonic band gap structures 2D. The study is carried out in consideration of wave propagation in a photonic crystal composed of GaAs columns equidistant from one another. This model extracts the band diagram for the lowest frequencies of the crystal.
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...
Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2020
This study tested the effectiveness of some natural ventilation basic configurations for the ther... more This study tested the effectiveness of some natural ventilation basic configurations for the thermal comfort of occupants in different local climates in Algeria. Due to the diverse Algerian climate, the study was performed during the mid-season period that includes three months of May, September, and October and the summer that includes the months of June, July, and August. The ventilation potential of the selected configurations was analysed through numerical simulation by using TRNSYS software coupled with COMIS aeraulic software. The results showed the significant contribution of natural chimney ventilation caused by a stairwell to improve occupant comfort. However; its integration requires a judicious and permanent inspection to control temperature decreases or overheating risks.
International Journal of Heat and Technology, 2021
Received: 10 May 2020 Accepted: 16 December 2020 The purpose of research presented in this paper ... more Received: 10 May 2020 Accepted: 16 December 2020 The purpose of research presented in this paper is to study the thermal and hydrodynamic effect of the non-isothermal laminar flow of a Al2O3-water nanofluid having shear thinning behavior in a mechanically stirred tank using the finite element method. Numerical simulation has been performed for a non-stationary two-dimensional flow controlled by certain influencing parameters such as the Reynolds number (1 ≤ Re ≤ 200), the behavior index (0.6 ≤ n ≤ 1) and the volume fraction of the alumina nanoparticles (0 ≤ φ ≤ 0.1). The simulation results obtained show that the addition of the Al2O3 nanoparticles in the base fluid leads to a significant enhancement in the heat transfer in the stirred tank compared to the base fluid. On the other hand, we note a slight decrease in the heat transfer with the decrease in the behavior index. It has also been noted, that the agitation power increases relatively with the volume fraction of the Alumina na...
The objective of this study is the comparison between the model of DarcyBrinkman and the Navier-S... more The objective of this study is the comparison between the model of DarcyBrinkman 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.
The objective of the present work is to study the effect of horizontal vibratory excitation on th... more The objective of the present work is to study the effect of horizontal vibratory excitation on the behavior of a water-Al2O3 nanofluid in natural convection in a cavity. The nanofluid used is composed of aluminum oxide nanoparticles in suspension of water, is provided at various volume fractions. The two horizontal walls are isothermal, maintained at cold temperature Tc and heat temperature Th. The two vertical walls are adiabatic. The basic equations describing the flow driven by natural convection consist of mass conservation, momentum and energy. For the physical parameters of Al2O3+water nanofluid, we use the Brinkman and Wasp model. Transport equations are solved numerically by finite element method. Results are presented in the form of streamlines, isotherms and the flux ratio.
In this work, a numerical study has been performed for the problem of steady-state natural convec... more In this work, a numerical study has been performed for the problem of steady-state natural convection in a square porous cavity having a solid wall of finite thickness and conductivity filled by a nanofluid in the presence of two isothermal cylindrical sources. The external walls of the cavity are considered adiabatic and the circular sources are maintained at a hot and cold uniform temperatures. The internal thick wall has been a conducting solid. The governing dimensionless equations are solved using Galerkin finite element method and Darcy-Brinkman model assumed to be adopted. The results are presented as isotherms, streamlines, stream function values, average and local Nusselt number for various combinations of Rayleigh and Darcy numbers, concentration of nanoparticles, Thermal conductivity ratio, and dimensionless wall thickness of the solid portion. The convection heat transfer can be enhanced by increasing of these parameters except for the wall thickness.
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.
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Papers by Mohammed ELMIR