非均质材料温度场的有限元算法

目前的热传导有限元方程以导温系数和等效表面散热系数作为基本参数，当用以计算比热和容重乘积相差较大的多种材料组成的非均质材料温度场问题时，会带来较大误差，有时会得出错误的结果。本文从热量平衡方程出发，提出了直接用导热系数、表出散热系数和热量为基本参数的热传导改进有限元算法。计算实例表明，本文方法可以正确地计算非均质材料或复合材料结构的温度场。

Improved FEM algorithm for calculating temperature field in heterogeneous material

The traditional FEM adopts thermal diffusivity and equivalent surface heat transfer coefficient as the primary parameters in calculation of heat conduction. It may result in remarkable error for heterogeneous structure composed of various media with different densities and heat capacities. Based on the equation for heat diffusion, a new FEM algorithm for calculating heat transmission in heterogeneous material is proposed. In the new method, the heat conductivity, surface thermal diffusivity and quantity of heat are adopted as the basic parameters for calculation. The validity of the proposed method is verified by an example. On this basis, the method is applied to calculate the temperature field in a dam with an insulating layer on the downstream surface. Reasonable result is obtained.