带尾缘劈缝冷气喷射的涡轮叶栅性能实验及计算

Numerical simulation and experiment for turbine cascade with trailing edge coolant injection

关键词:  涡轮叶栅  叶栅流  能量损失  数值仿真  叶栅  实验  气体喷射  气动特性

Key words:  Turbine cascade  Cascade flow  Energy loss  Numerical simulations  Cascade  Test  Gas injection  Aerodynamic characteristic

摘要:

通过平面叶栅实验和CFD数值计算方法,研究了叶片尾缘全劈缝冷气喷射下涡轮叶栅流场和气动性能。试验和计算发现,在冷气喷射条件下用不同损失系数描述涡轮叶栅性能,结论明显不同,用考虑冷气能量的能量损失系数评价气冷涡轮叶栅性能较为准确和客观。在较小的冷气流量下,劈缝冷气喷射使叶栅能量损失降低,尾缘劈缝冷气喷射可改善近尾迹区域的流动,减小尾迹亏损,降低尾迹掺混损失。尾缘劈缝冷气射流方向偏向叶片某型面,则尾迹损失峰值朝此型面偏移。

Abstract:

The linear cascade test and detailed numerical simulations were performed to study the effects of the injection coolant from trailing edge on the aerodynamic performance of turbine cascade.It was shown that there is obvious discrepancy in the effects of coolant injection on the total pressure loss coefficient and on the energy loss coefficient.It is possible to reduce the energy loss by improving wake flow structure with proper coolant flow mass and injection angle.The computed flow field shows the influence of the trailing edge injection deflected to pressure surface on the flow field of cascade is different from that of trailing edge injection deflected to suction surface.