燃气轮机叶轮非线性瞬态温度场的边界元分析

首先采用克希荷夫变换将包含变物性及混合和辐射边界条件的热扩散方程转换成线性方程，进一步由加权余量法和离散化将方程转变成边界元方程组。用所开发的二维线性—非线性瞬态温度场边界元程序分析计算了燃气轮机叶轮起动工况下的非稳态温度场，与有限元数值计算结果比较表明，边界元法应用于这类非线性工程问题的分析是可靠、初始精度高，数值稳定性好及计算输入数据简单等优点。

ANALYSIS OF NONLINEAR TRANSIENT TEMPERATURE FIELD IN A GAS TURBINE DISC WITH BEM

Kirchhoff's transform is employed to convert time dependent heat conduction equations,involving varying material properties and as well as radiation boundary condictions,into linear ones.Then the weighted residual method and discretization transform them into boundary element equations.On this basis,a 2-D linear/nonlinear transient temperature field analysis program has been set up to calculate the unsteady temperature field of a gas turbine disc in the starting regime.As compared with numerical results calculated with FEM,the results obtained show that the BEM method is reliable,and has many advantages,such as good initial accuracy and numerical stability,simplicity of input data preparation.Therefore,BEM is a very ideal numerical tool for analyzing gas turbine thermal problems.