气冷涡轮级叶栅非定常流场数值模拟

采用具有三阶精度TVD性质的有限差分格式、自由型曲面网格技术、分区算法以及双时间步长的方法,对某型涡轮级叶栅流场进行了非定常NS方程数值求解,考察了在有、无冷气喷射条件下涡轮级气动性能的非定常变化。结果表明,上游静叶栅是否喷射冷气对下游动叶栅超音速区域的影响具有明显的区别,有冷气喷射时动叶栅前缘气动负荷降低,级效率下降约1%,但是不同动叶通道内气动性能随时间周期性变化的幅度明显减小了。

NUMERICAL INVESTIGATION OF UNSTEADY FLOW FIELD IN A TURBINE STAGE WITH FILM-COOLING

An computational method based on 3D steady and unsteady N-S solver was adopted to simulate the flow field in film-cooling turbine, which included a finite difference scheme with 3rd order precision and TVD property, domain decomposition method, arbitrarily curved mesh technique and dual time step. The unsteady changes of aerodynamic parameters of the turbine stage with and without cooling were analyzed. The result shows that the influence of the upstream stator cascade trailing flow with cooling on the transonic region near rotor surface is distinctively different from that without cooling. When the upstream stator blade is cooled, the aerodynamic load on rotor blade and the averaged turbine stage effectiveness decreases about 1%, but the periodic fluctuations of the aerodynamic performance in different rotor passages are all reduced apparently.