涡轮蜂窝面径向轮缘密封封严性能的数值研究

Numerical Investigations on Sealing Performance of Turbine Honeycomb Radial Rim Seal

采用附加示踪变量方法,数值求解三维Unsteady Reynolds-Averaged Navier-Stokes（URA-NS）方程和SST紊流模型,研究了典型光滑面径向轮缘密封和新设计的蜂窝面径向轮缘密封的封严性能.数值计算了光滑面轮缘密封的封严效率.数值结果与实验数据吻合一致,验证了所发展数值方法的有效性.计算了三种封严冷气量下蜂窝面和光滑面径向轮缘密封的封严效率,分析对比了两种轮缘密封的封严性能和流场特性.研究结果表明：新设计的蜂窝面径向轮缘密封的封严效率相比于光滑面结构在相同冷气量下提高52%~67%.在径向内齿上开设蜂窝孔结构会增加流动阻力,抑制入侵燃气进入涡轮盘腔,有效地提高了轮缘密封的封严性能.

The sealing performance of the typical smooth and new designed honeycomb radial rim seal was numerically investigated using three-dimensional Unsteady Reynolds-Averaged Navier-Stokes （URANS） equations and SST turbulent model based on the Additional Passive Tracer Method. The sealing effectiveness of the experimental measurement rim seal was calculated using the presented numerical method. The numerical re-sults agree well with the experimental data. The validation of the developed numerical approach for the sealing ef-fectiveness was demonstrated. The sealing effectiveness of the smooth and honeycomb radial rim seal was comput-ed at three different coolant mass flow ratios. The sealing performance and internal flow field of the two kinds of ra-dial rim seals were also compared and analyzed. The numerical results show that the sealing effectiveness of the honeycomb radial rim seal is higher than that of the smooth design with 52%~67%at the same coolant mass flow ratio. The honeycomb structure would lead to increase of flow resistance in the radial clearance,which is benefi-cial to suppressing mainstream ingress into the turbine wheel disc and significantly increase the sealing perfor-mance by comparison of the typical smooth rim seal design.