端壁错位对端壁泄漏流冷却的影响研究

Effects of Endwall Misalignment on Endwall Purge Flow Film Cooling

本文采用数值方法针对燃气涡轮端壁因实际运行过程中部件热膨胀所造成的端壁错位进行了研究,详细分析了不同端壁错位形式下端壁上游槽缝泄漏流和槽缝/间隙泄漏流共同作用下的冷却分布规律。结果表明,端壁错位会改变端壁附近的流动结构,进而影响端壁表面泄漏流冷却的分布特性;在不同的端壁错位形式下,通道间隙泄漏流基本不会影响上游槽缝泄漏流的冷却分布;对上游槽缝泄漏流冷却有强化作用的端壁错位形式反而有可能会对端壁下游的间隙泄漏流冷却带来不利影响。

In this paper,film cooling performance from upstream slot purge flow with and without mid-passage gap leakage was numerically investigated in detail.The effects of endwall misalignment due to expansion and contraction of turbine component during engine operations were studied.The results show that the endwall misalignment significantly altered flow structures over the endwall surfaces and thus had obvious effects on cooling coverage over the endwall.At various misalignment modes,the gap leakage presented little effects on the purge flow cooling distributions from the upstream slot.The endwall misalignment,which improved the endwall purge flow cooling performance,could bring out a reduction in film cooling effectiveness from the mid-passage gap leakages.