脉冲进气条件下可调向心涡轮内部流场数值研究

Numerical Investigation on Pulsating Flow Field in Variable Nozzle Turbine

为评估可调向心涡轮在脉冲进气条件下的性能,通过对脉冲进气条件下的涡轮内部流场进行数值模拟分析,得到了脉冲进口压力对导流叶片段泄漏流量和总压损失、导流叶片尾缘激波强度及转子叶片前缘载荷的影响规律。导流叶片段泄漏流量和总压损失及激波随脉冲进口压力提高而线性增大,进口压力每提高10k Pa,泄漏流量增加约2.9%,导流叶片段的总压损失增加约2.7%,激波增强约14%;转子叶片前缘载荷也随脉冲进口压力增加而线性上升,当脉冲进口压力提高50k Pa时,转子叶片叶根前缘的载荷峰值增加约12.7%,中间叶高前缘位置的载荷峰值增加约24.9%。

To evaluate the aerodynamic performance of the variable nozzle turbine（VNT）radial turbine in pulsating inlet condition,the effects of pulsation pressure on the leakage flow and total pressure loss of the nozzle,the shock strength of nozzle trailing edge,the blade loading of the leading edge of the rotor blade are obtained by numerical method. The results show that the leakage flow of nozzle,total pressure loss and the shock strength increase linearly with the increase of turbine inlet pressure. The inlet pressure increases for each 10 k Pa,the leakage flow rate increases by about 2.9%,the total pressure loss of the nozzle increases about 2.7%,and the shock enhances about 14%. Meanwhile,the blade loading of the leading edge of the rotor blade also increases linearly with the increase of pulsation inlet pressure,when the pulsation pressure increases 50 k Pa,the blade loading peak of leading edge at the root of rotor blade increases by about 12.7%,and the value at the middle span of the blade increases about 24.9%.