M. Kriraa^1,2, M.EL Alami¹, M. Abouricha¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 443-464, 2014, DOI:10.3970/fdmp.2014.010.443

Abstract Natural Convection in a vertical channel with internal objects is encountered in several technological applications, among them particular interest of heat dissipation from electronic circuits, refrigerators, heat exchangers, nuclear reactors fuel elements, dry cooling towers, home ventilation, etc. This numerical study deals with the study of natural convection in a vertical convergent channel with a circular block. The considered parameters are 10⁴ ≤ Ra ≤ 10⁶, Prandtl number Pr = 0.71, channel height 10 ≤ A ≤ 30, inclination angle of the channel φ = 0,2.86°,5.74°. The size block conductivity and the block radius are assumed to be constant Λ… 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 on the dynamics… More >

A. B. Mahmud Hasan^1,2, S.M. Guo¹, M.A. Wahab¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.4, pp. 399-410, 2009, DOI:10.3970/fdmp.2009.005.399

Abstract The effects of gas flow channel design were studied experimentally for increasing fuel cell performance and fuel optimization. Three types of gas flow channels (serpentine, straight and interdigitated) were designed on the basis of water flooding due to electrochemical reactions, electro-osmotic drag, etc. Experimental results indicate that the best cell performance can be obtained by arranging interdigitated gas flow channel at the anode side and serpentine gas flow channel at the cathode side. Detailed analysis on complex two phase water generation and electrochemical phenomena behind those results were analyzed in this work to find out the best design for gas… More >

K.V. Pagalthivarthi¹, P.K. Gupta²

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 93-122, 2009, DOI:10.3970/fdmp.2009.005.093

Abstract The objective of the present work is to predict erosive wear in multisize dense slurry flow in a rotating channel. The methodology comprises numerical prediction of two-phase flow which is accomplished using the Galerkin finite element method. The wear models for both sliding wear and impact wear mechanisms account for the particle size dependence. The effect of various operating parameters such as rotation rate, solids concentration, flow rate, particle size distribution and so forth has been studied. Results indicate that wear rate in general increases along the pressure-side of the channel with rotation rate, overall solids concentration, flow rates etc.… More >

M. El Alami¹, E. A. Semma^2,3, M. Najam¹, R. Boutarfa²

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 23-36, 2009, DOI:10.3970/fdmp.2009.005.023

Abstract This study is devoted to the investigation of natural convection in a two dimensional horizontal channel with rectangular heated blocks at the bottom. The aspect ratio of the channel is A = L'/H' = 5. The blocks are heated with a constant temperature while the upper plane of the channel is cold. The governing equations are solved using a finite volumes method and the SIMPLEC algorithm is used for the treatment of the pressure-velocity coupling. Special emphasis is given to detail the effect of the Rayleigh number and blocks height on the heat transfer and the mass flow rate generated… More >

G. Accary¹, S. Meradji², D. Morvan², D. Fougère²

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.4, pp. 263-270, 2008, DOI:10.3970/fdmp.2008.004.263

Abstract In the literature, only few references have dealt with mixed-convection flows in the low Mach number approximation. For this reason, in the present study we propose to extend the standard 3D benchmark for mixed convection in a rectangular channel heated from below (Medale and Nicolas, 2005) to the case of large temperature variations (for which the Boussinesq approximation is no longer valid). The Navier-Stokes equations, obtained under the assumption of a low Mach number flow, are solved using a finite volume method. The results, corresponding to the steady-state case of the benchmark, lead to the idea of launching a call… More >

Lazhar Merouani¹, Belkacem Zeghmati², Azeddine Belhamri³

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.3, pp. 267-290, 2013, DOI:10.3970/fdmp.2013.009.267

Abstract The present work is a numerical study of laminar film condensation from vapor-gas mixtures in an inclined channel with an insulated upper wall and an isothermal lower wall coated with a thin porous material. A two-dimensional model is developed using a set of complete boundary layer equations for the liquid film and the steam-air mixture while the Darcy-Brinkman-Forchheimer approach is used for the porous material. The governing equations are discretized with an implicit finite difference scheme. The resulting systems of algebraic equations are numerically solved using Gauss and Thomas algorithms. The numerical results enable to determine the velocity, temperature and… More >

D. Cherrared¹, E. G. Filali¹

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.2, pp. 127-151, 2013, DOI:10.3970/fdmp.2013.009.127

Abstract Our study deals with the characterization of the flow and related heat transfer in a smooth, circular minichannel. A duct with a sudden (sharp-edged) contraction is also considered. Prediction of the pressure loss coefficient in this case is obtained via the commercial code CFX 5.7.1. This code is based on the finite volume method for the solution of the Navier-Stokes and offers several turbulences models (in this study we use the shear stress turbulence model - SST). The numerical results are compared with experimental results obtained for a configuration similar to those considered in the numerical study. The numerical algorithm… More >

S.-A. B. Al Omari^1,2, E. Elnajjar¹

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.2, pp. 91-109, 2013, DOI:10.3970/fdmp.2013.009.091

Abstract In a previous numerical study (Al Omari, Int. Communication in Heat and Mass Transfer, 2011) the heat transfer enhancement between two immiscible liquids with clear disparity in thermal conductivity such as water and a liquid metal (attained by co- flowing them in a direct contact manner alongside each other in mini channel) was demonstrated. The present work includes preliminary experimental results that support those numerical findings. Two immiscible liquids (hot water and liquid gallium) are allowed experimentally to exchange heat (under noflow conditions) in a stationary metallic cup where they are put in direct contact. The experimental results confirm the… More >

Emad Elnajjar¹, Mohammad O. Hamdan, Yousef Haik

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 77-89, 2013, DOI:10.3970/fdmp.2013.009.077

Abstract In this paper, two heat transfer configurations (central-jet and side-jet) of jet impinging on a semicircular surface are experimentally studied. The internal channel is formed using flat insulated wall and a semi-circular surface using a curved flexible heater with a uniform heat flux. A set of experiments have been performed for the purpose of assessing the heat augmentation and pressure drop between the two jet configurations. The measurements include the inlet and outlet flow temperatures using thermocouples, the temperature map of the flexible heater using thermal infra-red camera, the flow rates using rotary meter and pressure drop using pressure transducer.… More >