Casing treatments have been widely used in operation range extension of compressors or fans. However, if the extension is accompanied by aeroelastic instabilities like flutter, no improvement is achieved at all. Heretofore, the influence of casing treatments on aeroelastic stability as well as the underlying mechanism is still in doubt. In this paper, a transonic fan, NASA rotor 67, is used to investigate the influence of circumferential grooves on the aerodynamic and aeroelastic stabilities. The work is carried out numerically by solving three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations. The flutter behavior of the fan is analyzed by performing a unidirectional Fluid-Structure-Interaction (FSI) simulation. Energy method is adopted to obtain the normalized aerodynamic damping at different nodal diameters. The steady-state simulation results of smooth casing are firstly compared with the experiment to validate the accuracy and effectiveness of the Computational Fluid Dynamics (CFD) model. Then the comparison is performed both in aerodynamic and aeroelastic aspects. The results indicate that compared with smooth casing, the installation of circumferential grooves decreases the aeroelastic stability despite increased stall margin. The high-speed flow transported by the grooves from the pressure side of the blade improves the existing low-speed blockage in the blade tip at near stall point, thus delaying stall. However, the impingement of this high-speed flow on the leading edge of the suction side brings additional positive aerodynamic work on the blade, which leads to a decrease in the overall aeroelastic stability. Hence, the aeroelastic stability must be checked when introducing casing treatments for stall margin extension.

机壳处理已广泛应用于压缩机或风机的运行范围扩展。但是，如果扩展伴随着颤振等气动弹性不稳定性，则根本无法实现任何改进。迄今为止，套管处理对气动弹性稳定性的影响及其潜在机制仍存在疑问。在本文中，跨音速风扇，NASA 转子 67，用于研究圆周凹槽对空气动力学和气动弹性稳定性的影响。该工作通过求解三维雷诺平均纳维-斯托克斯 (RANS) 方程以数值方式进行。通过执行单向流固耦合 (FSI) 模拟来分析风扇的颤振行为。采用能量法获得不同节点直径下的归一化气动阻尼。首先将光滑套管的稳态模拟结果与实验进行对比，验证计算流体动力学（CFD）模型的准确性和有效性。然后在空气动力学和气动弹性方面进行比较。结果表明，与光滑套管相比，尽管增加了失速裕度，但圆周槽的安装降低了气动弹性稳定性。由叶片压力侧的凹槽输送的高速流改善了靠近失速点的叶片尖端现有的低速堵塞，从而延迟失速。然而，这种高速气流在吸力侧前缘的冲击会给叶片带来额外的正气动功，从而导致整体气动弹性稳定性的降低。因此，