基于CFD/CSD的非线性气动弹性分析方法

提出了一种基于计算流体力学/计算结构动力学(CFD/CSD)的非线性气动弹性分析方法,并应用于切尖三角翼的非线性颤振和极限环振荡(LCO)研究。该方法将非线性有限元(FEM)和CFD计算相结合,并辅以高精度的界面插值,能够分析结构和气动非线性共存的气动弹性问题。结构部分以四边形平板壳元为基础,采用更新的拉格朗日(UL)方法分析结构大变形引起的几何非线性问题。气动部分以Navier-Stokes(N-S)方程作为控制方程,采用CFD方法计算跨声速气动力。机翼的非线性颤振计算表明了方法的有效性。最后应用该方法研究了切尖三角翼的LCO现象,其计算精度明显优于已有结果。

Investigation of Nonlinear Aeroelastic Analysis Using CFD/CSD

A nonlinear aeroelastic analysis method using computational fluid dynamics/computational structure dynamics (CFD/CSD) is presented and applied to the nonlinear flutter and limit-cycle-oscillation (LCO) research of a cropped delta wing. This computational method couples a nonlinear finite element method (FEM) model with a CFD solver by using a high-fidelity interface interpolation, and is capable of investigating aeroelastic problems with both structural and aerodynamic nonlinearities. The structural analysis is based on a quadrilateral flat-shell element and an updated Lagrange (UL) formulation, which can be employed to model geometric nonlinearities arising from large deflections. With the Navier-Stokes (N-S) equations as the control equations, a finite volume CFD solver is formulated to calculate transonic aerodynamics. The nonlinear flutter calculation demonstrates the validity of the presented method. Finally the cropped-delta-wing LCO is computed, and the calculation precision is obviously better than the existing results.