骨架发热多孔介质方腔内非达西自然对流的数值研究  

Numerical Study of Non-Darcian Natural Convection in a Square Enclosure Filled with a Heat-Generating Porous Medium

作　　者：王刚[1] 曾敏[1] 王秋旺[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室

出　　处：《核动力工程》2007年第4期44-48,共5页Nuclear Power Engineering

基　　金：国家自然科学创新研究群体基金(50521604);国家教育部"新世纪优秀人才支持计划"(No.NCET-04-0938)资助

摘　　要：本文利用局部非热平衡模型,对骨架发热多孔介质方腔内的非达西自然对流进行了数值研究。方腔上下壁面绝热、左右壁面维持恒温T0。采用Brinkman-Darcy-Forchheimer模型来描述多孔介质内的流动,当有效导热系数比(0.001≤γ≤1.0)和无量纲容积换热系数(1.0≤H≤1000)在较宽的范围内变化时,计算研究了不同的有效导热系数比和无量纲容积换热系数对方腔内流动换热的影响。数值模拟结果表明:在有效导热系数比γ=1.0和无量纲容积换热系数H=1000时,局部热平衡模型是成立的;而对其他情形,必须采用局部非热平衡模型才能准确地预测出方腔内的流动换热特性。Steady non-Darcian natural convection in a square cavity, filled with a heat-generating porous medium is studied numerically by adopting the local thermal non-equilibrium model. The vertical walls maintain constant temperature To while the horizontal walls are considered to be adiabatic. The flow field is modeled by using the Brinkman-Darcy-Forchheimer model. Comprehensive numerical solutions are obtained in the wide range of two main dimensionless parameters, i.e. the effective fluid-to-solid thermal conductivity, ratio, 0.001 ≤ γ≤ 1.0, and the dimensionless volumetric heat transfer coefficient, 1.0 ≤ H≤ 1000. The effects of γand H on the flow and heat transfer characteristics are analyzed. It is found that the local thermal nonequilibrium model should be adopted at the low values of y and H for predicting the flow and heat transfer characteristics exactly.

关 键 词：骨架发热 局部非热平衡模型 多孔介质 自然对流 数值模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]