R. Djebali¹, M. El Ganaoui²

CMES-Computer Modeling in Engineering & Sciences, Vol.71, No.3, pp. 179-202, 2011, DOI:10.3970/cmes.2011.071.179

Abstract The Lattice Boltzmann method (LBM) became, today, a powerful tool for simulating fluid flows. Its improvements for different applications and configurations offers more flexibility and results in several schemes such as in presence of external/internal forcing term. However, we look for the suitable model that gives correct informations, matches the hydrodynamic equations and preserves some features like coding easily, preserving computational cost, stability and accuracy. In the present work, high order incompressible models and equilibrium distribution functions for the advection-diffusion equations are analyzed. Boundary conditions, acceleration, stability and preconditioning with initial fields are underlined which… More >

Massimo Corcione¹

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.2, pp. 175-200, 2011, DOI:10.3970/fdmp.2011.007.175

Abstract Free convection heat transfer in nanofluids from horizontal isothermal cylinders is investigated theoretically. The main idea upon which the present work is based is that nanofluids behave more like a single-phase fluid rather than like a conventional solid-liquid mixture. This assumption implies that all the convective heat transfer correlations available in the literature for single-phase flows can be extended to nanoparticle suspensions, provided that the thermophysical properties appearing in them are the nanofluid effective properties calculated at the reference temperature. In this connection, two empirical equations, based on a wide variety of experimental data reported… More >

M. Kriaa¹, M. El Alami^1,2, M. Najam¹, E. Semma³

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.2, pp. 125-140, 2011, DOI:10.3970/fdmp.2011.007.125

Abstract In this paper a numerical study of natural convection in a two dimensional convergent channel, with or without rectangular block, is carried out. The block is placed at the channel outlet and its thermal conductivity is set equal to that of air. One of channel planes is heated at constant temperature T_H. The other one is maintained cold at T_C < T_H. The governing equations are solved using a finite volume method and the SIMLEC algorithm for the velocity-pressure coupling is used. Special emphasis is given to detail the effect of the block size and Rayleigh number… More >

Hicham Rouijaa¹, Mustapha El Alami², El Alami Semma³, Mostafa Najam²

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.1, pp. 57-70, 2011, DOI:10.3970/fdmp.2011.007.057

Abstract This article presents a numerical study on natural convection in a bidimensional inclined "T"-shaped cavity. The governing equations are solved in the framework of a control-volume method resorting to the SIMPLEC algorithm (for the treatment of pressure-velocity coupling). Special emphasis is given to the investigation of the effect of inclination on the heat transfer and mass flow rate. Results are discussed for Prandtl number Pr=0.72, geometry with: opening width C=0.15, blocks gap D=0.5, blocks height, B=0.5 and different values of the Rayleigh number (10⁴ ≤ Ra ≤ 10⁶). More >

H. T. Chen¹,K. H. Hsu¹, S. K. Lee¹, L. Y. Haung¹

CMC-Computers, Materials & Continua, Vol.22, No.3, pp. 239-260, 2011, DOI:10.3970/cmc.2011.022.239

Abstract The inverse scheme of the finite difference method in conjunction with the least-squares scheme and experimental measured temperatures is proposed to solve a two-dimensional steady-state inverse heat conduction problem in order to estimate the natural-convection heat transfer coefficient under the isothermal situation [`h] iso from three vertical fins mounted on a vertical plate and fin efficiency hf for various values of the fin spacing and fin height. The measured fin temperatures and ambient air temperature are measured from the present experimental apparatus conducted in a small wind tunnel. The heat transfer coefficient on the middle More >

Patrick H. Oosthuizen^*, Jane T. Paul

Frontiers in Heat and Mass Transfer, Vol.1, No.1, pp. 1-8, 2010, DOI:10.5098/hmt.v1.1.3006

Abstract Natural convective heat transfer from narrow vertical plates which have a uniform surface heat flux has studied. With a narrow plate the heat transfer rate is dependent on the flow near the vertical edges of the plate. The magnitude of the edge effects will depend on the conditions existing near the edges of the plate. Three situations have here been considered these being a heated plate imbedded in a large plane adiabatic surface, the surfaces of the heated plane and the adiabatic surface being in the same plane, a heated plate with plane adiabatic surfaces More >

Han-Taw Chen¹, Li-Shie Liu¹, Shin-Ku Lee¹

CMES-Computer Modeling in Engineering & Sciences, Vol.65, No.2, pp. 155-178, 2010, DOI:10.3970/cmes.2010.065.155

Abstract The finite difference method in conjunction with the least-squares scheme and experimental measured temperatures is proposed to solve a two-dimensional steady-state inverse heat conduction problem in order to predict the natural-convection heat transfer coefficient under the isothermal situation h^−iso from a three fin array mounted on a horizontal plate and fin efficiency η_f for various values of the fin spacing and fin height. The measured fin temperatures and ambient temperature are obtained from the present experimental apparatus conducted in a small wind tunnel. The heat transfer coefficient on a fin is non-uniform for the present problem,… More >

Hao-Chueh Mai¹, Kuen-Hau Lin¹, Cheng-Hsiu Yang¹, Chao-An Lin^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.61, No.1, pp. 45-62, 2010, DOI:10.3970/cmes.2010.061.045

Abstract A thermal BGK lattice Boltzmann model for flows with viscous heat dissipation is proposed. In this model, the temperature is solved by a separate thermal distribution function, where the equilibrium distribution function is similar to its hydrodynamic counterpart, except that the leading quantity is temperature. The viscous dissipation rate is obtained by computing the second-order moments of non-equilibrium distribution function, which avoids the discretization of the complex gradient term, and can be easily implemented. The proposed thermal lattice Boltzmann model is scrutinized by computing two-dimensional thermal Poiseuille flow, thermal Couette flow, natural convection in a More >

S. Hamimid¹, A.Amroune¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.4, pp. 369-384, 2010, DOI:10.3970/fdmp.2010.006.369

Abstract The Navier-Stokes and energy equations are numerically solved to investigate two-dimensional convection (originating from the combined effect of buoyancy and surface tension forces) in a liquid metal subjected to transverse magnetic fields. In particular, a laterally heated horizontal cavity with aspect ratio (height/width) =1 and Pr=0.015 is considered (typically associated with the horizontal Bridgman crystal growth process and commonly used for benchmarking purposes). The effect of a uniform magnetic field with different magnitudes and orientations on the stability of the two distinct convective solution branches (with a single-cell or two-cell pattern) of the steady-state flows More >

S. Bouabdallah^1,2, R. Bessaïh¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.3, pp. 251-276, 2010, DOI:10.3970/fdmp.2010.006.251

Abstract In this paper, a numerical study of magnetohydrodynamics stability during phase change of a pure metal (liquid Gallium) in a cubical enclosure is presented. An external magnetic field is applied in X-, Y-, and Z-directions separately. Two electric potential boundary conditions are considered: electrically conducting and insulating walls. The finite-volume method with enthalpy formulation is used to solve the mathematical model in the solid and liquid phases. The Grashof number is fixed at Gr =105and the Hartmann number is varied from Ha= 0 to 200. The effect of magnetic field on the flow field and More >