关键词: 叶片式预旋喷嘴；叶孔式预旋喷嘴；流量系数；温降效率

Abstract: In order to investigate the effects of pressure ratio，Reynolds number and rotational speed on the nozzle discharge behavior and cover-plate pre-swirl system cooling performance，a pre-swirl system test rig run?ning at pressure ratio(π)1.1~1.5 and rotational speed 0~10kr/min was introduced first in the current study. Pres?sure and temperature distributions in a cover-plate system were measured to compare the performance of two types of vane pre-swirl nozzle(cascade vane nozzle and vane shaped hole nozzle). Numerical simulations were al?so performed to help analyze the physics of aerodynamic losses and cooling performance. Results show that the discharge coefficients of the two pre-swirl nozzles both increase slightly with the pressure ratio increase. As the Reynolds number rises，discharge coefficients increase first，and then remain constant when Re>2×105. In addi?tion，temperature drop effectiveness ηt of the system rises as the pressure ratio increases. With an increase in the rotation speed，the value of ηt would increase first and then decline at pressure ratio(π=1.5)，existing a maxi?mum value. Vane shaped hole nozzle and cascade vane nozzle have the similar discharge coefficient，both around 0.95. However，vane shaped hole nozzle has the advantage of reducing the secondary endwall flow loss and trail?ing edge loss，resulting in the significantly decreased deviation angle and increased swirl ratio at nozzle exit.Therefore，it could achieve an advanced cooling performance. At π =1.5 and ω =8.1kr/min，ηt for vane shaped hole nozzle is about 40% higher than that of cascade vane nozzle.

Key words: Cascade vane pre-swirl nozzle；Vane shaped hole pre-swirl nozzle；Discharge coefficient；Temperature drop effectiveness