1＋1／2对转涡轮高压动叶气膜冷却数值研究

NUMERICAL PREDICTION OF FILM-COOLING ON THE HIGH PRESSURE ROTOR OF A 1+1/2 COUNTER-ROTATING TURBINE STAGE AT DESIGN AND OFF-DESIGN CONDITIONS

对1+1/2对转涡轮高压动叶设计了冷却方案,在高压动叶前缘滞止线,压力面和吸力面分别开设了冷却孔,并对冷却方案进行了三维数值模拟。为了研究变工况下,高压动叶气膜冷却性能,对三种典型的工况进行了详细的数值模拟。研究了不同转速对高压动叶前缘冷却效果的影响。以及吹风比对高压动叶前缘气膜冷却效果的影响;给出了前缘、压力面、吸力面冷气射流的流动特征;分析了冷气喷射对高压动叶型面马赫数,型面压力的影响。最后探讨了高压动叶吸力面后部70%轴向弦长处冷气喷射对高压动叶通道内波系结构的影响。

Numerical simulations were performed to predict the film cooling effectiveness on the leading edge of the high pressure rotating blade in a 1＋1/2 counter-rotating turbine stage using NUMECA/FINETURBO software with S-A turbulence model. Simulations were performed for both the design and off-design conditions to investigate the effects of blade rotation on the leading edge film cooling effectiveness.It was found that the tilt stagnation line on the leading edge of rotor moves from the pressure side to the suction side, and the instantaneous coolant streamlines shift from the suction side to the pressure side with increasing rotating speed. The effect of blowing ration on the film cooling effectiveness of leading edge and suction side were also been investigated. Flow character of the coolant on the leading edge, pressure side and suction side were given. Finally, the effect of coolant injection on the pressure and relative Ma distribution of the high pressure rotor blade were considered.