This article proposes a numerical investigation into the internal flow structure in the supersonic expander-rotor (SER). In order to reveal internal flow mechanism, the significant influencing factors in the flow structure are identified, and the solutions to improving the integrated performance of the SER are developed. According to the numerical results, the wave structure of the expansion wave and the oblique shock wave is what characterizes the flow in the mainstream region of the SER. In addition, the expansion wave and the oblique shock wave impose control on the pattern of static pressure distribution in the 3-D channel and then the 3-D flow structure. The formation and breakdown of the tip leakage vortex are the main form that the motion of vortex takes in the SER. The concentration, recirculation, and separation of the boundary layer; the low energy fluid mixing with mainstream; and the interaction between the oblique shock waves and the boundary layer are the crucial motion tracing near the endwall. Compared with the traditional turbines, the flow structures in the tip region of the SER are relatively simpler; the essential motion tracing is the airflow near the leading edge of the strake wall moving from the PS through the tip gap to the SS as a result of the transverse pressure difference.

本文提出了对超音速膨胀转子 (SER) 内部流动结构的数值研究。为了揭示内部流动机制，确定了流动结构中的重要影响因素，并开发了提高SER综合性能的解决方案。根据数值结果，膨胀波和斜激波的波结构是表征SER主流区流动的特征。此外，膨胀波和斜激波控制了 3-D 通道中的静压分布模式，进而控制了 3-D 流动结构。叶尖泄漏涡流的形成和击穿是涡流运动在SER中的主要形式。边界层的浓缩、回流和分离；与主流混合的低能流体；斜激波与边界层的相互作用是端壁附近的关键运动轨迹。与传统涡轮机相比，SER尖端区域的流动结构相对简单；基本的运动轨迹是由于横向压力差，靠近板壁前缘的气流从 PS 通过尖端间隙移动到 SS。