考虑辐射效应的多孔材料传热有限元算法

应用有限元法求解一维半透明多孔介质辐射对流传热问题。通过对辐射传递方程与边界条件中积分项的离散 ,推导出有限元求解列式。对于多孔介质传热控制方程和气体传热控制方程的求解 ,采用时间积分技术对两相温度统一进行求解。而对于边界方程处理 ,则通过传热方程与边界方程的循环求解 ,求出任意时刻温度场的瞬态解。给出数值算例 ,得出了放置在通风口、同时受到伴随辐射作用的半透明多孔介质传热的瞬态解 ,讨论了部分参数对瞬态温度场以及换热效果的影响

Finite Element Method for Heat Conduction Analysis in Porous Media with Consideration of Radiative Effects

A finite element method for the computation of coupled heat transfer problems in the translucent porous medium was developed.Deducing control equations to the finite element computing forms was realized.Transient solutions of heat transfer through a translucent porous medium placed in a flow passage and submitted to incident radiation were obtained.The one-dimensional physical model took into account simultaneously the heat conduction,convection and radiation in the porous medium,which was assumed to be homogenous continuum,absorb,emit,and scatter thermal radiation.The coupled equations of conductive and convective heat transfer have to be solved simultaneously.Some techniques were used so that the coupled equations and the radiation heat transfer equation could be transformed into the computing forms.The initial temperature conditions were introduced in the iterative computation,and thus the transient solutions were obtained using time integration technique.The effects of some material parameters on transient temperatures were investigated by numerical computations.