基于流固耦合的斜激波冲击作用下曲壁板气动弹性分析

采用自主发展的双向流固耦合求解器,研究了斜激波冲击作用下曲壁板的气动弹性响应特性。曲壁板的几何非线性大变形运动方程采用有限差分法求解,流体控制方程基于有限体积法求解,双向流固耦合采用交错迭代算法。计算结果表明:当动压小于临界颤振动压时,曲壁板表现出静平衡状态,且随着动压的增大,壁板变形的非对称性越明显。当动压大于临界颤振动压时,壁板振动位移先增大后减小,最终达到稳定颤振状态,且该极限环颤振并不关于初始位置正负对称的。同时,随着动压的增大,壁板颤振的正向峰谷值、负向峰谷值和振幅均逐渐增大,颤振频率则逐渐减小。壁板振动响应规律并不随着壁板弯曲高度的改变而单调递增或递减,较小的弯曲高度可以降低壁板颤振临界动压值,但是当弯曲高度进一步增大后,由于气动非线性特性增强,准周期无规则运动状态被激发了出来,临界颤振动压迅速升高。

Aeroelastic analysis of curved panels subjected to impinging, oblique shock based on fluid-structure coupling algorithm

A developed fluid-structure coupling solver was used to study the aeroelastic response behaviors of curved panels subjected to an impinging oblique shock. The geometric nonlinear large deformation equations of curved panel were solved by finite difference method,while the fluid governing equations were solved by means of finite-volume scheme. The conventional serial staggered algorithm was adopted for the fluid-structure interaction. Numerical results demonstrated that as the dynamic pressure was smaller than the critical flutter dynamic pressure, the curved panel exhibited a static equilibrium state,and the asymmetry of the panel deformation was more pronounced with the increasing dynamic pressure. When the dynamic pressure was greater than the critical flutter dynamic pressure, the panel vibration displacement increased firstly and then decreased,and finally reached a stable flutter state. This limit cycle flutter was asymmetric about the initial point. Meanwhile,as the dynamic pressure increased,the maximum positive and negative displacements of panel flutter,and flutter amplitude increased gradually,but the frequency of flutter reduced gradually. The panel flutter behaviors did not monotonously increase or decrease with altering curvature of panel. The smaller initial curvature can reduce the critical dynamic pressure of panel flutter. However,as the panel curvature further increased,the quasi-periodic irregular oscillation was excited due to the enhancement of the aerodynamic nonlinearity,and the critical dynamic pressure rose rapidly.