关键词: 多孔介质层, 冲击射流, 基于预处理的时间推进法, 流动与换热特性

Abstract: The preconditioned density-based algorithm and two-domain approach were used to investigate the fluid flow and heat transfer characteristics of confined laminar impinging jet on a plate covered with porous layer.In the porous zone, the momentum equations were formulated by Darcy-Brinkman-Forchheimer model, and the thermal equilibrium model was adopted for energy equation.At the porous/fluid interface, the influence of stress-jump interfacial condition was analyzed.The governing equations were solved by preconditioned density-based infinite-volume method, with preconditioning matrix for equations of porous domain adopted, aiming to eliminate the equation stiffness of porous seepage flow.The effects of Reynolds number, porosity, Darcy number, ratio of thermal conductivities, and porous layer thickness on the flow pattern and local heat transfer were studied.Results indicate that Reynolds number and porosity do not influence the flow pattern of porous channel strongly, while the effects of Darcy number and porous layer thickness are significant.All the parameters mentioned above have obvious influence on local overall heat transfer performance.

Key words: porous layer, impinging jet, preconditioned density-based algorithm, fluid flow and heat transfer characteristics