Effects of casing cooling slot purge on heat transfer in turbine blade tip and casing

Abstract

In recent years, heat transfer in turbine tips and casings has received extensive attention. To further improve heat transfer in the casing region, casing cooling slot purge is proposed as a strategy to effectively control the high heat load. In this study, the effects of different cooling groove geometries and aerodynamic parameters on the heat transfer coefficient and net heat load reduction of the blade tip and casing cooling efficiency are compared numerically when the outlet isentropic Ma is 0.96. The results show that the casing cooling slot purge can realize cooling of the casing, tip groove surface, and tip area of the suction surface. A better cooling effect could be obtained by reducing the coolant slot angle at the same flow rate. By increasing the coolant injection angle, the cooling efficiency of the casing and the inner surface of the groove is improved.

Keywords:

• Casing purge
• heat transfer
• numerical simulation
• tip leakage flow
• turbine blade

Additional information

Funding

This work is supported by the National Natural Science Foundation of China (Grant Nos. 52076052 and U2233207).