切尖三角翼极限环振荡的气动弹性模拟

 建立了高精度的气动弹性计算模型,对切尖三角翼风洞试验中的极限环振荡（LCO）现象进行数值模拟。结构部分引入大变形产生的几何非线性和塑性引起的材料非线性,气动部分采用Euler方程描述跨声速流动。结构/气动交界面精确匹配,并选取三维插值进行界面载荷传递。依据所建模型分析切尖三角翼的颤振和LCO,并与试验值进行比较。在小来流动压情况下,结构几何非线性引起了切尖三角翼的LCO,计算结果和试验值吻合较好。在大来流动压情况下,结构材料非线性导致了LCO幅值的急剧增大,其变化趋势与试验观察相符。研究结果显示,切尖三角翼的LCO不仅与结构几何非线性密切相关,而且受到结构材料非线性的显著影响。

Aeroelastic Simulation of Limit-cycle-oscillation of a Cropped Delta Wing

This article presents numerical simulations of the limit-cycle-oscillation (LCO) behaviors of a cropped delta wing observed in a transonic wind tunnel test by means of a high-fidelity aeroelastic analysis model. In the computational model, the structural part includes the geometric nonlinearity arising from large deflection and the material nonlinearity originated from plasticity, while the aerodynamic part employs the Euler equations to describe the transonic flow. In addition, the interfaces between the structural and aerodynamic domains are built in the form of an exact match where load transfer is performed based on 3D interpolation. The flutter and the LCO of the cropped delta wing are calculated and the results are compared with existing experimental measurements. For lower inflow dynamic pressures, the LCO of the delta wing is caused by structural geometric nonlinearity, and the numerical results correlate well with experimental data. For higher dynamic pressures, the structural material nonlinearity leads to a rapid rise in LCO amplitude, and the varying trend is consistent with experimental observation. The study shows that the LCO of a cropped delta wing is not only closely related to its geometric nonlinearity, but also remarkably affected by its material nonlinearity.