高压涡轮全环非定常流动数值模拟

为了进一步准确地掌握涡轮内部复杂流动特征,采用全环非定常数值模拟方法研究了某型高压涡轮内部非定常流动,重点分析了上游导叶尾迹和激波在动叶流动中的非定常作用机制,探讨了引起动叶通道内及叶片表面压力分布周期性变化的非定常扰动。数值结果表明:与尾迹作用相比,由导叶激波引起的非定常效应更为明显,尾迹引起的非定常扰动在动叶0.5倍轴向弦长位置下游较为突出。在动叶流场中及叶片表面上的静压变化显示,在动叶通道内还存在低频扰动,对局部流场的非定常扰动明显。最后指出,在非定常计算时采用区域缩放法对流场中非定常扰动的预测存在一定误差。

Numerical Simulation of Full Scale Unsteady Flow in High Pressure Turbine

In order to study the complicate flow characteristic in the turbine, the unsteady flow was studied in high pressure turbine by the full scale unsteady flow numerical simulation. The unsteady mechanism of upstream IGV wakes and shock in the rotor flow was analyzed, and the periodically unsteady perturbation which causes the change of blade passage flow and blade surface pressure distribution was discussed. The simulation results show that the unsteady effect caused by IGV shock is more obvious, compared with the wake effect,unsteady perturbation induced by wake is more prominent in the downstream of 1/2 axial chord. The pressure distribution in the rotor flow field and on the surface of blade shows that, in the rotor flow field there is a low frequency fluctuation, which causes unsteady perturbation significantly on the local flow field. It is pointed out that certain error exists when predicting the unsteady perturbation using domain scaling method.