跨声压气机近失速流动特征的数值模拟研究

Numerical Study of Near-Stall Flow Feature on

关键词:  轴流压气机  突尖型失速  数值模拟  失速先兆  相关性系数

Key words:  Axial flow compressor  Spike stall  Numerical simulation  Stall inception  Correlation coefficient

摘要:

为了研究跨声轴流压气机突尖型失速先兆的表现形式与演化规律，探索较为可行的先兆探测方法，对NASA Rotor 37转子近失速工况下的流场进行了三维全环非定常的数值模拟。数值模拟结果表明，在失速团产生之前的约2转时间内，存在一个失速扰动相对缓慢增长的阶段。更早时刻发生的流量持续下降是导致失速团最终形成前缘溢流出现的原因。使用不同的方法对前缘附近机匣处的静压数值探针信号进行处理，探索了各种方法的优缺点，并且发展了一种互相关分析方法，能够取得较好的扰动识别效果。

Abstract:

Three-Dimensional full-annulus time-accurate numerical simulation of the NASA Rotor 37 flow at near-stall condition has been carried out for the purpose of exploring the evolution pattern and feasible detection method of spike-like rotating stall inception in the transonic axial flow compressor. Simulation results show that there is a stage when stalling perturbations grow slowly in approximately 2 revolutions before the first stall cell appears. The leading edge spillage，which eventually leads to the formation of stall cells，is actually the result of continuously decreased mass flow rate which appears at earlier moments. Static pressure signals from numerical probes located on the casing just upstream of the blade leading edge were processed and carefully studied by various methods. It is shown that a new cross-correlation method developed by the author shows better capability in the identification of pre-stall perturbations among the studied methods.