径流式涡轮三维温度场分析

高温径流涡轮承受很高的热应力,新一代的陶瓷涡轮由于燃气初温高,以及材料固有的热脆性,使温度场、热应力的研究在陶瓷涡轮的设计中更占有重要的地位。本文用三维有限元法分析了陶瓷和金属材料的径流涡轮温度场。为了确定热传导边界条件,作者用准正交面流线曲率法确定势流流场,接着用边界层能量积分方程计算了叶轮壁面的放热系数,从而建立了一个从径流涡轮流动计算到温度场分析的软件包。计算结果表明,温度梯度的最大值出现在近叶片根部。此外,气流出口处的轮毂部分温度梯度也较大。这些地方将是应力集中区。

Analysis of Three-Dimensional Temperature Distribution in Radial Turbine

In regard to the high inlet temperature and inherent brittleness of ceramic material,the analysis of temperature distribution and thermal stress plays a dominant role in the design of turbine engines with ceramic components.In this paper,a 3D finite element analysis was carried out for the prediction of the temperature field of a ceramic and steel radial turbine disk.For studying the heat conduction boundary conditions,the arbitrary quasi-orthogonal surface method was used to describe the potential flow patterns.Then energy integral equations of the boundary layer were adopted to calculate the local heat transfer coefficients on the surface of the turbine so that a software package containing programs from aerodynamic calculation to determination of temperature distribution in a radial turbine wheel could be performed.The results showed that the maximum temperature gradients took place near the root of blade as well as the exit in the hub,where the maximum thermal stresses could be expected.