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Hassan Naji

Bio: Hassan Naji is an academic researcher from Artois University. The author has contributed to research in topics: Lattice Boltzmann methods & Heat transfer. The author has an hindex of 14, co-authored 38 publications receiving 580 citations. Previous affiliations of Hassan Naji include Lille University of Science and Technology & university of lille.

Papers
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TL;DR: In this paper, a two-dimensional double Multiple Relaxation Time-Thermal Lattice Boltzmann Equation (2-MRT-TLBE) method is developed for predicting convective flows in a square differentially heated cavity filled with air.

142 citations

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TL;DR: In this paper, a numerical analysis of the two-dimensional flow and heat transfer in a horizontal channel differentially heated and obstructed by an inclined square cylinder mounted to the approaching flow with an angle of inclination equal to 45° is carried out.

53 citations

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TL;DR: In this paper, the numerical solution for natural convection and volumetric radiation in an isotropic scattering medium within a heated square cavity using a hybrid thermal lattice Boltzmann method (HTLBM) was presented.
Abstract: This paper deals with the numerical solution for natural convection and volumetric radiation in an isotropic scattering medium within a heated square cavity using a hybrid thermal lattice Boltzmann method (HTLBM). The multiple relaxation time lattice Boltzmann method (MRT-LBM) has been coupled to the finite difference method (FDM) to solve momentum and energy equations, while the discrete ordinates method (DOM) has been adopted to solve the radiative transfer equation (RTE) using the S8 quadrature. Based on these approaches, the effects of various influencing parameters such as the Rayleigh number ( Ra ), the wall emissivity ( e ι ), the Planck number ( Pl ), and the scattering albedo ( ω ), have been considered. The results presented in terms of isotherms, streamlines and averaged Nusselt number, show that in absence of radiation, the temperature and the flow fields are centro-symmetrics and the cavity core is thermally stratified. However, radiation causes an overall increase in the temperature and velocity gradients along both thermally active walls. The maximum heat transfer rate is obtained when the surfaces of the enclosure walls are regarded as blackbodies. It is also seen that the scattering medium can generate a multicellular flow.

47 citations

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TL;DR: In this paper, a numerical study was carried out for conjugate natural convection-surface radiation heat transfer from a heated circular cylinder enclosed in a square cavity using a hybrid scheme with lattice Boltzmann for fluid velocity variables and finite difference for the temperature.
Abstract: A numerical study is carried out for conjugate natural convection–surface radiation heat transfer from a heated circular cylinder enclosed in a square cavity. A hybrid scheme with lattice Boltzmann for fluid velocity variables and finite difference for the temperature is used. The vertical walls of the enclosure are cooled with a uniform temperature while the others are adiabatic. Effects of the Rayleigh number, size and location of the heated cylinder and surface emissivities are investigated numerically. The results are reported in terms of isotherms, streamlines and the average Nusselt number. It is found that (i) the radiation exchange standardizes the temperature inside the cavity and produces an increase in the heat transfer, particularly at large Ra, (ii) the heat transfer enhances with increasing cylinder size and/or surface emissivity and (iii) the maximum rate of heat transfer occurs when the cylinder is located at the horizontal median close to the vertical wall.

45 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of the change of the aerodynamic flow (in the steady and unsteady cases), the variation of parameters of the movement (angle of attack, pitch angle and yaw angle) and the definition of subsystems characteristics that makes the wind turbine (blade, nacelle and pylon) allow one to characterize the structural dynamic behavior of the wind turbines.
Abstract: The study of the dynamic behavior of a wind turbine with horizontal axis can be undertaken by various methods of analysis. The effects of the change of the aerodynamic flow (in the steady and unsteady cases), the variation of parameters of the cinematic movement (angle of attack, pitch angle and yaw angle) and the definition of subsystems characteristics that makes the wind turbine (blade, nacelle and pylon) allow one to characterize the structural dynamic behavior of the wind turbine. It is therefore necessary to develop these items. Once this is done, the structural dynamic behavior of the system can be improved. The term `improve' means the increase of the life duration by mastering the fatigue effects and the reduction of cost without sacrificing the aerodynamic output. The present study aims to examine the behavior of the blade, which is the main part of the wind turbine in that it that transmits forces to all other parts of the structure. The model is based on the theory of three-dimensional beams, under the assumption of variable sections of the type NACA 4415 airfoil, and takes into account membrane, transversal shear, flexion and free torsion effects. With regards to the aerodynamic loads (the lift, the drag and the pitching moment), a validation has been undertaken by considering experimental data and numerical results obtained by a CFD code (Fluent). The forces are obtained by means of a parametric CAD method interpolation of the aerodynamic poles by Bezier patch under geometrical constraints solved by a Simplex type algorithm. The emphasis is put on dynamic aspects by a complete processing of the dynamic equilibrium equation, applied to the wind turbine blade with horizontal axis.

42 citations


Cited by
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01 Jan 2016

1,633 citations

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TL;DR: A comprehensive review of the lattice Boltzmann (LB) method for thermofluids and energy applications, focusing on multiphase flows, thermal flows and thermal multi-phase flows with phase change, is provided in this paper.

618 citations

Journal ArticleDOI
TL;DR: This review aims to provide a practical and accessible introduction to both the experimental and numerical state-of-the-art, intended for students and researchers with backgrounds in experimental geo-sciences or computational sciences alike.

336 citations

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TL;DR: In this article, the phase change heat transfer in porous phase change materials (ss-PCMs) is discussed and a review of the recent experimental and numerical investigations is presented, which shows that the pore-scale simulation can provide extra flow and heat transfer characteristics in pores, exhibiting great potential for the simulation of mesoporous, microporous and hierarchical porous materials.
Abstract: Latent heat thermal energy storage (LHTES) uses phase change materials (PCMs) to store and release heat, and can effectively address the mismatch between energy supply and demand. However, it suffers from low thermal conductivity and the leakage problem. One of the solutions is integrating porous supports and PCMs to fabricate shape-stabilized phase change materials (ss-PCMs). The phase change heat transfer in porous ss-PCMs is of fundamental importance for determining thermal-fluidic behaviours and evaluating LHTES system performance. This paper reviews the recent experimental and numerical investigations on phase change heat transfer in porous ss-PCMs. Materials, methods, apparatuses and significant outcomes are included in the section of experimental studies and it is found that paraffin and metal foam are the most used PCM and porous support respectively in the current researches. Numerical advances are reviewed from the aspect of different simulation methods. Compared to representative elementary volume (REV)-scale simulation, the pore-scale simulation can provide extra flow and heat transfer characteristics in pores, exhibiting great potential for the simulation of mesoporous, microporous and hierarchical porous materials. Moreover, there exists a research gap between phase change heat transfer and material preparation. Finally, this review outlooks the future research topics of phase change heat transfer in porous ss-PCMs.

259 citations