考虑表面粗糙度影响的低温涡轮泵特性与动静间隙流动分析

To analyze the effects of surface roughness of flow passage component on cryogenic turbopump performance and explain the influence mechanism of surface roughness on rotor-stator centripetal flow, a cryogenic turbopump made of shrouded impeller produced by additive manufacturing is selected as the research object, and the experimental tests and numerical calculations on the performance of cryogenic turbopump are carried out taking into consideration the influence of thermodynamic effects and using liquid nitrogen as the pressurizing and conveying medium. The results show that when the test working condition is in the range of 13 500 to 26 000 r/min, the values of outlet pressure and temperature rise obtained by numerical calculation are fitted with the test data after considering the effects of the surface roughness, compared with the numerical results obtained from smooth wall setting. As the values of the impeller and volute surface roughness increase to 36 μm, the head coefficient and efficiency decrease by 9.1% and 10.6%, respectively. The axial thrust acting on the impeller decreases significantly by 25.8%, after increasing the values of the rotor-stator surface roughness from 0 to 20 μm. The study provides a theoretical foundation for revealing the influence of surface roughness on cryogenic turbopump flow characteristics and zoned controlling the surface quality of the turbopump flow passage components.