跨声速流中圆锥孔在涡轮动叶叶顶上的气膜冷却特性实验研究

The film cooling characteristics of a turbine blade tip with conical holes are experimentally stud⁃ ied in transonic flow. The pressure sensitive paint technique is used to analyze effects of mass flow ratios and den⁃ sity ratios on the film cooling effectiveness distribution of the squealer tip with conical holes. The cascade inlet Reynolds number is 3.68×10⁵ based on the chord length，and the cascade exit Mach number is 1.05. The experi⁃ ment is carried out at three mass flow ratios of 0.1%+0.05%，0.14%+0.07%，and 0.21%+0.105%，and three den⁃ sity ratios of 1，1.5，and 2. The results show that the lower the mass flow ratio，the stronger the guidance action of conical holes，increasing the coolant coverage on the blade tip. However，the coolant is concentrated in bunches and ejected from the conical hole at the high mass flow ratio，which has a negative effect on the film coverage on the blade tip. With the density ratio increasing，the film cooling performance of the blade tip is improved，particu⁃ larly at the high mass flow ratio.