考虑变比热的冷却涡轮弯曲叶栅流场的数值模拟

对采用弯曲叶片的某型高压涡轮导向器有／无冷气喷射时的栅内流场进行了数值模拟。应用了以冷气源项反映冷气掺混影响的三维变比热计算方法。结果表明，弯曲叶栅内的冷气喷射导致了马赫数和温度的变化；叶片表面和端壁得到有效的低温保护；在相同冷气流量下，压力面附近温度降低较吸力面明显，冷却气膜的作用也更为有效；栅内二次流对冷气分布有影响。

Numerical Simulation of a Cooled Turbine Curved Cascade Flow Field with Variable Specific Heat Being Taken into Account

A numerical simulation is conducted with respect to an in-cascade flow field of a high-pressure turbine nozzle assembly of curved vanes in the case of the presence and absence of an air cooling spray. A three-dimensional variable specific heat computation method has been employed with the cooling air source reflecting the cooling air mixing/dilution effect. The calculation results show that the cooling air spray in the curved cascades led to a change in Mach number and temperature with the blade surface and end wall obtaining an effective low-temperature protection. Under the same cooling air flow rate the temperature reduction near a pressure side appears to be more marked than at the suction side with the cooling air film playing a more effective role. The in-cascade secondary flow exercises an influence on the cooling air distribution.