高效气动优化设计方法

摘要

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.%Large scales of computations are required in aerodynamic optimization based on CFD methodologies.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 parameterized 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 configuration.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.