湍流、转捩模型对气冷涡轮气热耦合计算影响的对比研究

Contrast Study of the Influence of the Turbulent Flow and Transition Model on the Gas-heat Coupled Calculation of an Air-cooled Turbine

开发了基于三维非结构网格的导热求解程序,将数值解与解析解对比验证了加权最小二乘法相对于格林函数法在求解梯度时具有更高的精度,将基于加权最小二乘法的三阶精度的导热程序与叶栅流场计算程序HIT-3D耦合,实现了气热耦合计算,对MARKII叶片5411实验工况进行了数值模拟,并借助于HIT-3D程序具备的湍流模型研究了转捩对传热计算的影响。结果表明:BL模型预测的温度与实验值相差最大,在转捩点相差10%,BL+AGS转捩模型、SST-Gama模型、q-ω模型由于具备模拟转捩的能力,因此在转捩区计算的温度误差较小,约5%,可见考虑转捩的湍流模型能更好地预测涡轮叶片的温度。

Developed was a heat conduction solution-seeking program based on the three-dimensional non-structural grid.Through a contrast with the analytic solutions,it has been verified that the weighted least square method has a higher precision than the Green function method when seeking solutions to the gradient.The heat conduction program with a three-order precision based on the weighted least square method was coupled with the program HIT-3D for calculating the flow field in cascades to accomplish a gas-heat coupled calculation.The 5411 test conditions for MARKII blades were numerically simulated and with the help of the turbulent flow model available in the program HIT-3D,the influence of the transition on the heat transfer calculation was studied.It has been found that the temperature predicted by using the BL model has a greatest difference from the test value,being up to 10% at the transition point.As the software has an ability to simulate the transition,the temperature error in the transition zone calculated by using the BL + AGS transition model,SST-Gama model and q-ω model is relatively small,being around 5%.It can be seen that the turbulent flow models with the transition being taken into account can better predict the temper-ature on turbine blades.