跨音速流动中涡轮动叶叶顶的气膜冷却特性分析

Film cooling characteristics analysis of turbine blade tip in transonic flow

为了掌握跨音速流动中涡轮动叶叶顶气膜冷却特性,采用压敏漆测试技术来研究叶顶间隙高度和质量流量比对叶顶气膜冷却特性的影响规律。研究结果表明:在小质量流量比条件下,增加叶顶间隙高度能够有效改善叶顶中弦区域的气膜覆盖,然而当质量流量较大时,叶顶间隙高度变化对叶顶中弦区域的气膜冷却效率分布影响并不明显;在小叶顶间隙高度条件下,随着质量流量比增加,叶顶中弦区域冷气覆盖效果逐渐变差,在大叶顶间隙高度条件下,仅当质量流量比从0.1%+0.05%增加到0.14%+0.07%时,叶顶中弦区域的冷气覆盖效果才有所改善。

To grasp the film cooling characteristics of the turbine blade tip in transonic flow,the pressure sensitive paint technique was used to experimentally obtain the effects of the tip clearance gap and mass flow ratio on the film cooling performance of the blade tip.The results indicate that,under conditions of low mass flow ratio,increasing the tip clearance height effectively enhances the film coverage in the mid-chord region of the blade tip.However,when the mass flow ratio is high,changes in the tip clearance height have an insignificant effect on the distribution of film cooling efficiency in this region.Under conditions of small tip clearance heights,the cooling coverage in the mid-chord region deteriorates gradually as the mass flow ratio increases.In contrast,with larger tip clearance heights,an improvement in cooling coverage is only observed when the mass flow ratio increases from 0.1%+0.05%to 0.14%+0.07%.