关键词: 风沙颗粒, 气固两相流, 气膜孔堵塞, 气动性能, 冷却性能

Abstract: To investigate the reduction in cooling efficiency caused by the deposition and blockage of sand particles in the film cooling holes of turbine blades when aero-engines operate in sandy environments, this study focuses on the structure of cylindrical film cooling holes. A numerical simulation method based on the computational fluid dy鄄 namics-discrete phase model (CFD-DPM) is adopted to explore the gas-solid two-phase flow characteristics ofsand particles inside the film cooling holes. By combining particle motion trajectory analysis with a deposition kinetics model, the deposition characteristics of sand particles in the film cooling holes and the mechanism by which they affect cooling performance are systematically studied. The results show that the positions where sand particles collide with and deposit on the wall inside the film cooling holes mainly occur at 30%of the leeward side wall surface near the inlet of the film cooling holes and at the trailing edge of the outlet of the film cooling holes, mak鄄 ing the internal and trailing edge regions of the film cooling holes prone to blockage. Trailing edge blockage changes the flow structure of the cooling air flow, leading to a decrease in the adherence effect of the cooling air flow to the wall; a relatively high proportion of trailing edge blockage (B > 0.3) significantly reduces the cooling performance (with a reduction of more than 20%). Blockage inside the film cooling holes does not affect the adherence of the air flow to the downstream wall and has a relatively limited impact on the overall cooling performance.

Key words:  , sand particles, gas-solid two-phase flow, film cooling hole blockage, aerodynamic performance, cooling perfor mance