含集中质量不同流向多通道旋转输流管动力学特性分析

Dynamic Characteristics Analysis of Multi-Channel Rotary Flow Tube with Concentrated Mass and Different Flow Directions

摘要: 涡轮叶片工作环境极度严苛，需要在内部设置多条冷却通道使其冷却降温。叶片在自身旋转和内部流体的共同作用下，会引发系统共振，因此需要对叶片的动力学行为进行研究。本文主要研究旋转叶片在内部流体作用下产生的动力学行为，将含有叶冠和蛇形冷却通道的叶片结构简化为含端部集中质量不同流向多通道旋转输流管，通过计算位移分量在轴向拉伸和弯曲变形的作用下产生的动能、势能以及开放系统下流体作用对系统产生的功，代入Lagrange方程得到系统的动力学方程，将方程无量纲化，使其具有一般性规律。通过求解动力学方程的特征值，计算得到系统的特征频率和阻尼频率。研究结果表明：旋转输流管中流体流速方向会显著影响系统的特征轨迹和振动模态，转速和端部集中质量会显著提高输流管的稳定性。

Abstract: The working environment of turbine blades is extremely harsh, and multiple cooling channels need to be set up inside to cool them. Under the joint action of blade rotation and internal fluid, the system resonance will be triggered, so it is necessary to study the dynamic behavior of blade. This paper mainly studies the dynamic behavior of rotating blades under the action of internal fluids. The blade structure containing blade crown and serpentine cooling channels is simplified into a multi-channel rotating flow tube with concentrated mass at the end in different directions. Kinetic energy and potential energy generated by the displacement component under the action of axial stretching and bending deformation and the work generated by fluid action on the system under an open system are calculated. The Lagrange equation is substituted to obtain the kinetic equation of the system, and the equations are dimensionless, so that they have general laws. By solving the eigenvalues of the dynamic equations, the eigenfrequencies and damping frequencies of the system are calculated. The results show that the characteristic trajectory and vibration mode of the system are significantly affected by the flow velocity direction in the rotating flow tube, and the stability of the flow tube is significantly improved by the rotational speed and end mass.