The present paper numerically investigates the rotating stall mechanism in the NASA CC3 transonic centrifugal compressor with wedge-type vaned diffuser. The three-dimensional compressible, unsteady Navier–Stokes equations have been applied to a full-annulus high-speed centrifugal compressor comprising an inlet duct, impeller, and vaned diffuser. The scale-adaptive simulation model is selected as the turbulent closure model. The aim of this paper is to predict and capture the key features of rotating stall in a transonic high-pressure centrifugal compressor based on the scale-adaptive simulation approach. First, the steady numerical model was validated by the experiment for the aerodynamic compressor performance at different operating conditions from choke to surge. Then, unsteady simulations were conducted near the surge point to propose a detailed analysis of stall characteristics within the compressor diffuser passages. Comparison of the unsteady pressure signals with those of the measurement data revealed that the numerical results matched well with the experimental data to capture the rotating speed of the stall cells. Time/space analysis of transient entropy production distribution was performed within the diffuser passages to show the stall behavior and to confirm the existence and development of rotating stall cells during the impeller revolutions. Evaluation of the spectral analysis of the computed pressure fluctuation by the current numerical approach showed reasonable agreement with the experimental data for blade passing and rotating stall frequencies. The present paper demonstrates that the current numerical model is a beneficial engineering approach to provide accurate solutions compared to experimental data for prediction of the rotating stall as well as to resolve the unsteady turbulence structures.

本文对具有楔形叶片扩压器的NASA CC3跨音速离心压缩机的旋转失速机理进行了数值研究。三维可压缩的非稳态Navier-Stokes方程已应用于包括入口导管，叶轮和叶片式扩散器的全环高速离心压缩机。选择适应尺度的模拟模型作为湍流闭合模型。本文旨在基于尺度自适应仿真方法，预测并捕获跨音速高压离心压缩机中旋转失速的关键特征。首先，通过实验验证了稳态数值模型在从节流阀到喘振的不同工况下的气动压缩机性能。然后，在喘振点附近进行了非稳态模拟，以详细分析压缩机扩压器通道内的失速特性。非稳态压力信号与测量数据的比较表明，数值结果与实验数据吻合得很好，以捕捉失速室的旋转速度。在扩散器通道内进行了瞬态熵产生分布的时间/空间分析，以显示失速行为并确认叶轮旋转过程中旋转失速单元的存在和发展。通过当前数值方法对计算出的压力波动的频谱分析进行评估，显示出与叶片通过和旋转失速频率的实验数据合理吻合。