S型进气道对风扇叶片振动的影响（英文）

Effects of S-shaped Duct on Fan Blade Vibration

S型进气道广泛应用于现代航空发动机。其气流转角及进气道引起的流动畸变现象能导致叶片振动问题发生,如叶片颤振和强迫响应。本文考虑了S型进气道的影响,分析风扇叶片的振动特性。采用S型进气道与Rotor67风扇叶片相结合的模型,使用课题组内基于流固耦合算法的气动弹性分析程序,对风扇叶片进行气动弹性分析。在流体域内,使用基于有限体积法的三维非结构化网格的可压缩流体求解器,结构动力学求解器采用模态叠加方法求解叶片振动。进气道与风扇交界面处采用掺混面和滑移面两种处理方法,分别代表不考虑进气道的影响和考虑进气道及流动畸变的影响。计算对比了两种情况下的气动阻尼值,并分析了风扇叶片对进气道的瞬态响应。本文证明了S型进气道能够增加叶片强迫响应及引发叶片颤振,对风扇叶片的振动造成严重的影响。

S-shaped intakes are commonly used in modern aero-engine designs. The flow distortion induced by flow turning and duct effects could lead to the blade vibration problems, such as blade flutter and forced response. This paper analyzes the vibration characteristics of fan blades with the effects of a S-shaped intake interaction. Using a coupled CFD/CSD numerical code,aeroelasticity analysis of the rotor67 fan with an S-shaped duct is conducted. The in-house numerical code featured a three-dimensional unstructured finite-volume compressible flow solver in the fluid domain and a structure dynamic solver with the modal superimposition method for blade vibration. A mixing-plane model is used at the interface between intake domain and fan domain in order to model the blade vibration without interaction with the duct.Asliding-plane model is used at same condition to include the flow distortion and duct effects on the fan blade motion. The overall aerodynamic damping of the rotor blade is presented for both cases. The transient response of the fan with the intake is analyzed. This study proves the S-shaped duct intake interaction has significant impact on the blade vibration by increasing forced response and causing flutter.