高效气动优化设计方法

基于CFD方法开展气动外形优化设计通常计算量较大,采用离散共轭方法计算目标函数梯度,建立了高效的飞机气动优化设计系统。采用NURBS方法对翼剖面几何外形的扰动量进行参数化,避免了对原始外形的拟合,建立了基于NURBS方法的机翼剖面参数化方法。在复杂外形的优化设计中,动网格方法是关键技术之一,采用无限插值方法生成变形后的网格,并提出采用无限插值方法处理部件之间相贯线发生变化的情况。最后开展了翼身组合体+吊舱+挂架等复杂外形的优化设计,成功地减小了阻力,证明了方法的有效性。

Efficient Aerodynamic Design Optimization of Complex Configuration

Large scales of computations are required in aerodynamic optimization based on CFD methodol- ogies. Efficient aerodynamic design optimization system is built in this paper, and the gradients of object functions are calculated with discrete adjoint method. The geometric perturbations of wing sections are pa- rameterized with NURBS method,furthermore parameterization methodology of wing based on NURBS are built. Moving grid is one of key technologies in aerodynamic optimization design of very complex configu- ration. Transfinite interpolation methodology is utilized to generate new grid, and a methodology based on transfinite interpolation technology is proposed to deal with the surface grid in the case of junction lines varying. Configurations including wing- body- nacelle- pylon are optimized with the design optimization system. The drag is reduced successfully, which illustrates the effectiveness of the methodology built in this paper.