开裂式阻力方向舵流固耦合机理分析

为了探究阻力方向舵开裂状态下的流场形态和流固耦合运动机理，采用计算流体力学(CFD)方法开展了不同开裂角下的二维阻力方向舵的流场计算。基于动力学模态分解(DMD)方法对各流场进行模态分解，分析了各模态的流动特征及频率变化。结果表明，在20°开裂角的范围内，机翼绕流的流场结构以开裂区内的驻涡及后缘脱落涡为主，流场各阶模态频率随来流速度的增大而增大，随开裂角的增大而减小。同时，对不同开裂角的二维翼型开展了流固耦合计算。结果表明, 随着折减速度的增加，系统的流固耦合运动形式由涡致振动发展为流动失稳，系统的失稳边界随着开裂角的增大而提高。 

Fluid and structure coupling analysis of split drag rudder

To explore the flow field morphology and fluid-structure coupling mechanism of split drag rudder, computational fluid dynamics (CFD) method is used to calculate the SDR flow field with different crack angles. Based on the dynamic mode decomposition (DMD) method, the flow characteristics and frequency variations of each mode are analyzed. Results show that at the crack angle of 20°, the flow field structure around the wing is mainly composed of the standing vortex in the crack area and the trailing edge shedding vortex, and that the modal frequencies increase with the increase of incoming flow velocity and decrease with the increase of the crack angle. Then the fluid-structure interaction of SDR with different crack angles is calculated. The results show that with the increase of the reduction velocity, the fluid-structure interaction mode of the system develops from the vortex induced vibration to flow instability, and that the instability boundary of the system increases with the increase of the crack angle.