带冷气掺混的涡轮级流场数值模拟

Numerical Simulation of Turbine Stage with Cooling Gas Injection

为了实现对带冷气掺混的涡轮级流场的数值模拟 ,利用 Jameson有限体积方法在 H型结构化网格上求解 Reynolds平均 Navier-Stokes方程组。根据混合平面假设实现涡轮级 (导向叶片 /转子 )动静流场的联算。采用一维等熵流动模型求解冷却气体在冷却孔出口的流动参数 ,并通过在边界注入相应的通量引入冷却气体对主流流场的影响。通过对典型算例计算 ,获得与实验吻合的结果。验证了本文方法的可行性和计算精度。基于此 ,本文对亚音速和跨音速两组涡轮级的带冷气掺混的三维流场进行了粘流流场和换热分析 ,获得了合理的计算结果。

In order to numerically simulate the viscous flow field in the turbine stage with cooling gas injection, the Jameson's finite volume method is employed to solve Reynolds averaged Navier-Stokes Equations on H type structural grid generated with the elliptical method. For the simplicity and robustness of the software, the Baldwin-Lomax algebraic model is chosen for turbulence closure. According to the so called one-dimension isentropic flow model, the mass, momentum, and energy flux injected through film cooling holes or slots to the flow field are computed and then coupled to the boundary conditions to reveal the effects of cooling gas. Using the mixing plane model makes the simulation of stator-rotor interaction be realized with acceptable computer resource costs. A typical configuration - C3x cascade with film cooling, which has experimental data, is computed to validate the present methods. Results of both flow field parameters and heat transfer parameters are in good agreement with experimental data. To illustrate the present methods' capability of handling configurations with engineering complexity, simulation results of two realistic turbine stages, a transonic one and a subsonic one, both with complex layout of cooling holes and slots, are presented.