轴流压气机失速点流场特性数值研究

Numerical Investigation of Flow Field Characteristics at Near Stall Condition in Axial Compressor

通过对三个单转子跨声速轴流压气机的数值模拟,考察了近失速点的流场特征。结果表明,Vo等人提出的尖峰型失速判别准则,即前缘溢流和尾缘倒流必须都出现则失速发生,并没有与本文所有算例吻合;在部分算例中,尾缘倒流并未出现。因此,尾缘倒流是发生尖峰型失速的必要条件、还是失速发生后所导致的流动状况,还需要进一步研究。另外,还对亚声速和跨声速情况下近失速点的流场及流动机制进行了讨论。

In order to understand the flow field characteristics at near stall condition in axial compressors, numerical simulations of three axial-flow compressor rotors were performed. It demonstrated that the criteria for spike-type rotating stall developed by Vo et al, i.e., the spillage of tip clearance fluid ahead of blade leading edge and the reverse flow at trailing edge plane, are not suitable for all the test cases. In some numerical results, the reverse flow at trailing edge below the blade tip is not observed at near stall conditions. Therefore, it needs further investigations to identify whether the reverse flow at trailing edge of rotor at near stall condition can be regarded as one of the criteria, which characterizes the onset of spike stall. In addition, the flow field structures and the detailed mechanisms at near stall point in both subsonic and transonic conditions arc discussed.