The 90-degree bend is one of the basic connection components applied in industrial flowing systems. This bend influences the aerodynamic performance of the downstream connecting equipment. In this study, the performance of a two-stage axial compressor with a 90-degree bend inlet was numerically and experimentally analyzed under low rotating speed. The testing results show that the outflow of the bend was numerically non-uniform in the circumferential and radial directions. To analyze the performance influence of the bend on the downstream compressor, a full passage compressor model with and without the inlet bend was simulated. The size of the distortion region gradually spread to the entire cascade, and the intensity of the distortion obviously dropped after the first stage as the compressor ran with the bend. The deterioration of the compressor performance, especially in the first stage, was verified numerically and experimentally. The total pressure coefficient and isentropic efficiency decreased by 2.6 % and 1.13 %, respectively. To save simulation cost, a model with a downstream single blade passage and cylindrical inlet was proposed, and the distorted flow was set as the inlet boundary condition. In addition, the unsteady numerical simulation was performed with the rotating inlet distortion region. Compared with the full blade passage model, the unsteady single blade passage model obtained the downstream spread characteristic of the distortion and performance deterioration. The latter can therefore be suggested as a compromised approach for obtaining the propagation characteristics of the inlet distortion with acceptable accuracy and low computational cost.

90度弯曲是应用于工业流动系统的基本连接组件之一。该弯曲影响下游连接设备的空气动力学性能。在这项研究中，在低转速下通过数值和实验分析了具有90度弯角入口的两级轴流式压缩机的性能。测试结果表明，弯头的流出在周向和径向上在数值上是不均匀的。为了分析弯头对下游压缩机的性能影响，模拟了带有和不带有进口弯头的全通道压缩机模型。变形区域的大小逐渐扩展到整个级联，并且随着压缩机随着弯道运行，变形的强度在第一阶段后明显下降。数值和实验验证了压缩机性能的下降，尤其是在第一阶段。总压力系数和等熵效率分别降低了2.6％和1.13％。为了节省仿真成本，提出了具有下游单叶片通道和圆柱形入口的模型，并将变形的流设为入口边界条件。另外，对旋转的入口变形区域进行了非稳态数值模拟。与全叶片通道模型相比，非稳态单叶片通道模型获得了变形和性能下降的下游扩展特性。