压气机失速先兆及转子多工况流场的DMD分析  

DMD analysis of compressor stall inception and rotor flow field under multiple conditions

作　　者：李康迪 杜云祥 徐自力[1] LI Kangdi;DU Yunxiang;XU Zili(State Key Laboratory for Strength and Vibration of Mechanical Structures,School of Aerospace Engineering,Xi'an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学航天航空学院,机械结构强度与振动国家重点实验室,西安710049

出　　处：《航空动力学报》2020年第11期2413-2420,共8页Journal of Aerospace Power

基　　金：国家自然科学基金(51675406)。

摘　　要：对NASA Rotor 37跨声速轴流压气机级在多工况下的非定常流场进行了流固耦合数值模拟,采用动力学模态分解(DMD)方法得到了流体压力和速度的模态信息并绘制了模态云图,数值判定了压气机各工况的稳定性,获得了流动特征结构,通过模态云图发现了近失速点突尖型失速的初期表现。结果表明:在计算的多种工况中,近失速点和堵塞点均存在不稳定的模态阶次;DMD方法识别的各阶频率与压力信号频谱分析结果的最大误差为0.63%;随着背压上升,相邻两叶片通道内高压低速流体团位置逐渐向叶片前缘移动,范围逐渐扩展;在近失速点,尾缘回流与主流的掺混在叶片吸力面中部产生了半椭球形的旋涡并造成流道堵塞,是突尖型失速的初期表现。The unsteady flow field of a transonic axial compressor Rotor 37 was numerically simulated, and the modal information of fluid pressure and velocity were obtained by the dynamic modal decomposition method(DMD). The stability of the compressor under different working conditions was determined, the main characteristic structures of the flow field were captured, and the stall aura of the compressor was found by the modal cloud diagram. The results showed that, the near stall point and the plugging point had unstable modal orders;the maximum error between DMD frequency and pressure spectrum was 0.63%;with the rise of backpressure, the fluid mass in the two adjacent blades gradually moved to the leading edge of the blade, and its range was expanded;at the near stall point, with the mixing of main flow and reflux, a semi-ellipsoidal vortex was generated in the middle of the blade suction surface and the flow channel was blocked, which was the initial manifestation of a spike stall.

关 键 词：跨声速轴流压气机 非定常流场 动力学模态分解 模态特征分析 突尖型失速 

分 类 号：V231.3[航空宇航科学与技术—航空宇航推进理论与工程]