基于流固耦合的激波/边界层干扰作用下壁板颤振特性

Panel flutter characteristics on shock wave/boundary layer interaction based on fluid⁃structure coupling

为了解激波/边界层干扰作用下壁板气动弹性及其对流动分离的影响,采用自主开发的双向流固耦合求解器,对不同激波冲击位置下壁板的振动响应和流动特性进行了数值模拟研究。壁板几何非线性运动方程采用有限差分法求解,基于有限体积法求解Navier-Stokes方程组,对流通量采用MUSCL和AUSMPW+格式离散,双向流固耦合采用交错迭代算法。研究结果表明:激波/边界层干扰作用下壁板振动位移先增大后减小,经若干振荡周期后达到稳定颤振状态,呈现二阶振动模态,壁板变形相对于激波冲击位置呈现非对称性,壁板前部分的振幅始终小于壁板后部分;激波冲击位置可显著改变壁板的颤振振幅、频率及分离区长度,当激波冲击位置靠近壁板两端时,壁板振动最终收敛达到静稳定状态;壁板振动响应与流场特征不随激波冲击位置的改变而单调变化,对于激波冲击位置x/a=0.35工况,壁板颤振可有效抑制激波/边界层干扰流动分离。

To analyze the aeroelastic stability of the flexible panel in shock wave/boundary layer interaction and its influence on flow separation,a developed fluid-structure coupling solver is used to numerically simulate the vibration response and flow characteristics of the flexible panel at different shock impingement locations.The geometrically nonlinear equations of the flexible panel are solved by the finite difference method,Navier-Stokes equations based on the finite volume method,and MUSCL and AUSMPW+schemes are used for the discretization of convective flux.The conventional serial staggered algorithm is adopted for the fluid-structure interaction.The results exhibit that the vibration displacement of the panel increases first and then decreases,and reaches a stable flutter state after several oscillation cycles,with a second-order vibration mode.The deformation of the panel is asymmetric relative to the shock impingement location.The amplitude of the front part of the panel is always smaller than that of the rear part of the panel.The shock position can significantly change the flutter amplitude,frequency,and separation zone length of the panel.When the shock impingement location is close to both ends of the panel,the vibration of the panel finally converges with the change of the shock impact position.For shock impingement location xi/a=0.35,the panel flutter can effectively suppress flow separation in shock wave/boundary layer interaction.