三维机翼气动结构多学科优化方法

采用Euler方程、连续伴随优化方法、自由形面变形技术（free-form deformation,FFD）以及一种四边形线性壳单元模型对三维机翼气动结构多学科优化方法开展了研究。目标函数为阻力系数和机翼翼盒结构质量的加权和,设计变量为FFD控制点以及10段蒙皮的厚度。气动方面升阻力系数对设计变量的梯度由伴随方法求得,结构方面翼盒质量对于蒙皮厚度的梯度可直接计算,应力的梯度采用有限差分方法获得。对跨声速大展弦比机翼进行气动结构多学科优化,并将该计算结果与机翼气动单学科优化设计后的静气弹计算结果进行对比,结果表明:该气动结构多学科优化方法能够在满足约束条件下,实现阻力系数和翼盒质量同时降低,保证优化结果的合理性。 

Aero-structural multi-disciplinary optimization method for three-dimensional wing

An aero-structural multi-disciplinary optimization method for 3D wing was developed using Euler equations, continuous adjoint method, FFD(free-form deformation) strategy and a linear quadrilateral shell model. The objective function is the weighted sum of drag coefficient and the structural weight of the wing box. The design variables include the control points of FFD volume and the thicknesses of ten skin segments. The gradients of lift coefficient and drag coefficient with respect to design variables were adopted by continuous adjoint method, the gradients of wing box weight were acquired directly, and the gradients of the stress were obtained with finite difference method. The aero-structural multi-disciplinary optimization method was applied to a high aspect ratio wing in transonic regime, and a comparison between the results from aero-structural analysis of single-disciplinary optimization and aero-structural optimization was presented. It showed that the drag coefficient and the weight can decrease simultaneously through aero-structural optimization while the constraints were satisfied to keep the results reasonable.