外形参数化方法对气动优化过程的影响

探讨了各类参数化方法(包括PARSEC,CST,HicksHenne,自由型变形等)的原理、优缺点及其对气动优化设计的影响。首先简述了基于NS方程进行气动优化设计的过程,指出参数化方法为优化问题提供了设计变量。然后研究了各类参数化方法的原理,给出了各类方法中参数的几何意义,并对PARSEC方法提出了改进。通过比较各类方法对代表性翼型的重构能力,给出了合理选择参数化方法,参数个数及其取值范围的建议。最后给出了在相同工况下分别使用Hicks-Henne和PAR-SEC两种参数化方法的气动减阻优化结果,研究了其对翼型气动优化效率和效果的影响。

EFFECT OF SHAPE PARAMETERIZATION ON AERODYNAMIC SHAPE OPTIMIZATION

This paper studies the effect of shape parameterization on automatic aerodynamic shape optimization based on discussion and comparison of various methods, including PARSEC method, CST method, Hicks-Henne bump functions, free-form deformation, etc. First, the complete formulation of the optimal design process using the Navier-Stokes equations is presented and the role parameterization played is pointed out. Second, by comparing these techniques based on the accuracy they can construct several kinds of representative airfoils, advices concerning which parameterization method to be adopted and how to specify number and scope of variables are given. Improvement for the PARSEC method is also given. Finally, results are presented for drag minimization problems by using Hicks-Henne and PARSEC respectively, other conditions being equal, which illustrates the influence of parameterization on the efficiency and effect of airfoil optimization.