高径位供气孔结构对涡轮轮缘密封特性的影响

To investigate the detailed design of turbine rim seal，a high-radial sealing hole structure was presented on the basis of the radial rim seal configuration， and the hole was considered as the main sealing flow path. The effects of circumferential injection angle and the number of holes on the sealing efficiency and unsteady flow characteristics in the wheel-space were studied using the experimentally validated unsteady Reynolds-average Navier-Stokes (URANS) numerical method， and the influence mechanisms of the hole structure on the instability flow structure and the degree of gas ingestion in the wheel-space were analyzed. The results showed that the change of circumferential injection angle of the hole can optimize the sealing efficiency by 10.15%， and also can reduce it by 8.32% in the worst case. Negative injection angle of the hole enhanced the unsteady effect in the wheel-space， accompanied by stronger fluid shear， which led to an increase in the scale of the Kelvin-Helmholtz instability vortex structure， the increase of gas ingestion and decrease of sealing efficiency. Positive injection angle of the hole made the relative velocity direction of the mixed fluid more uniform，which reduced the scale of the Kelvin-Helmholtz instability vortex structure; the degree of gas ingestion was weakened，and the sealing efficiency was improved. Increasing the number of holes reduced the jet momentum of sealing flow，which led to an increase in the scale of the Kelvin-Helmholtz instability vortex structure in the wheel-space，intensified the depth of gas ingestion and also reduced the sealing efficiency，which，however，was higher than that of the rim seal without holes.