Rotating stall is one of the most important sources of performance deterioration and system instability in axial flow compressors and, therefore, it is of great value for compressor aerodynamic design and the development of active control strategies. It has been widely demonstrated that peculiar flow mechanisms, such as tip clearance leakage vortices, play a decisive role in the genesis of rotating instabilities (RI) and stall inception, however it is still very hard to predict and interpret such mechanisms accurately. This paper presents the results of both experimental and numerical researches dealing with forming process of rotating stall in a 1.5-stage low-speed industrial axial compressor at Harbin Engineering University. A new physical mechanism for explaining the birth of rotating instabilities based on the detection of spike waves is introduced as a result of a deep analysis recognising the role due to low-energy flow migration of along the rotor spanwise direction. To this purpose, transient pressure signals obtained from both experiments and simulations were adopted to describe flow details during onset and scanning pressure contours on the compressor casing were obtained both experimentally and numerically during the process of approaching stall point so that the transition process from RI to the appearance of spike waves could be well captured. The experimental results showed that the frequencies of RI dropped nearly linearly against the flow coefficient and the strength of radial secondary flows increased distinctly, which induces the boundary layer separation near leading edge in the tip region at last. Full-annulus URANS numerical simulations using SST turbulence model were performed and validated adequately by test data, and then employed to capture more flow details and support better understanding of the flow physics. In fact, a lateral tornado-type vortex occurring before the trailing edge backflow and featuring the same frequency of early pressure disturbances was observed numerically. Under the combined effect of the lateral tornado-type vortex and the tip secondary vortex, a trailing edge reverse flow was observed which produced a huge increase of blockage. A radial tornado vortex was formed connecting the suction side and casing wall at the same time finally leading to the spike-wave rotating stall.

旋转失速是轴流压缩机性能下降和系统不稳定的最重要原因之一，因此，它对于压缩机的空气动力学设计和主动控制策略的开发具有重要的价值。已经广泛地证明了特殊的流动机制，例如尖端间隙泄漏涡流，在旋转不稳定性（RI）和失速开始的起因中起着决定性的作用，但是仍然很难准确地预测和解释这种机制。本文介绍了哈尔滨工程大学1.5级低速工业轴流式压缩机旋转失速形成过程的实验和数值研究结果。作为深入分析的结果，引入了一种新的物理机制，用于解释基于尖峰波的旋转不稳定性的产生，该深入分析认识到了沿转子翼展方向的低能流迁移所起的作用。为此，采用从实验和模拟获得的瞬态压力信号来描述启动过程中的流量细节，并在接近失速点的过程中通过实验和数值方式获得了压缩机壳体上的压力轮廓扫描图，从而实现了从RI过渡到RI的过程。尖峰波的出现可以很好地捕获。实验结果表明，RI的频率相对于流量系数几乎呈线性下降，径向次流强度明显增加，最终在尖端区域的前缘附近引起边界层分离。进行了使用SST湍流模型的全环URANS数值模拟，并通过测试数据进行了充分验证，然后将其用于捕获更多流动细节并支持对流动物理学的更好理解。实际上，从数值上观察到了在后缘回流之前发生的侧向龙卷风型旋涡，并且具有相同的早期压力扰动频率。在侧向龙卷风型涡旋和尖端次级涡旋的共同作用下，观察到了后缘逆流，从而大大增加了阻塞。形成了同时连接吸力侧和套管壁的径向龙卷风涡流，最终导致尖峰波旋转失速。进行了使用SST湍流模型的全环URANS数值模拟，并通过测试数据进行了充分验证，然后将其用于捕获更多流动细节并支持对流动物理学的更好理解。实际上，从数值上观察到了在后缘回流之前发生的侧向龙卷风型旋涡，并且具有相同的早期压力扰动频率。在侧向龙卷风型涡旋和尖端次级涡旋的共同作用下，观察到了后缘逆流，从而大大增加了阻塞。形成了同时连接吸力侧和套管壁的径向龙卷风涡流，最终导致尖峰波旋转失速。进行了使用SST湍流模型的全环URANS数值模拟，并通过测试数据进行了充分验证，然后将其用于捕获更多流动细节并支持对流动物理学的更好理解。实际上，从数值上观察到了在后缘回流之前发生的侧向龙卷风型旋涡，并且具有相同的早期压力扰动频率。在侧向龙卷风型涡旋和尖端次级涡旋的共同作用下，观察到了后缘逆流，从而大大增加了阻塞。形成了同时连接吸力侧和套管壁的径向龙卷风涡流，最终导致尖峰波旋转失速。然后用于捕获更多的流细节并支持对流物理学的更好理解。实际上，从数值上观察到了在后缘回流之前发生的侧向龙卷风型旋涡，并且具有相同的早期压力扰动频率。在侧向龙卷风型涡旋和尖端次级涡旋的共同作用下，观察到了后缘逆流，从而大大增加了阻塞。形成了同时连接吸力侧和套管壁的径向龙卷风涡流，最终导致尖峰波旋转失速。然后用于捕获更多的流细节并支持对流物理学的更好理解。实际上，从数值上观察到了在后缘回流之前发生的侧向龙卷风型旋涡，并且具有相同的早期压力扰动频率。在侧向龙卷风型涡旋和末梢副涡旋的共同作用下，观察到后缘逆流，这大大增加了阻塞。形成了同时连接吸力侧和套管壁的径向龙卷风涡流，最终导致尖峰波旋转失速。在侧向龙卷风型涡旋和尖端次级涡旋的共同作用下，观察到了后缘逆流，从而大大增加了阻塞。形成了同时连接吸力侧和套管壁的径向龙卷风涡流，最终导致尖峰波旋转失速。在侧向龙卷风型涡旋和尖端次级涡旋的共同作用下，观察到了后缘逆流，从而大大增加了阻塞。形成了同时连接吸力侧和套管壁的径向龙卷风涡流，最终导致尖峰波旋转失速。