叶顶流场的自激非定常流动普遍存在于压气机动叶内部。本文以非定常数值模拟为基础,通过对比一系列压气机动叶叶顶数值流场的主导频率,对不同工况、不同几何结构压气机叶顶自激非定常流动提出一致的解释模型,以补充现有的叶顶自激非定常流动机理。研究发现,自激非定常的频率及产生位置与叶顶低速团密切相关。在不同的工况下,间隙流动、角区流动及两者的相互作用都会影响叶顶低速团的生成周期及形态,最终决定叶顶自激非定常流动的频率及影响范围。

The self-induced unsteadiness can be found in the tip region of an axial compressor. In this paper, based on the unsteady Reynolds averaged simulation, the numerical results with different operation condition and tip clearance size were obtained. Then, by comparing the leading frequency of the unsteady tip leakage flow in the rotor tip region, the self-induced flow was well understood. It was found that the low-velocity cell is highly related with the frequency and amplitude of the self-induced unsteadiness in the rotor tip region. Under different operation conditions, the period and the characteristic of the low-velocity cell are influenced by the tip leakage flow, the separation flow and their interactions, which determines the frequency and the amplitude of the self-induced unsteadiness in the tip region.

工信部重大专项基础研究项目(2017-II-0006-0019)