多目标自然层流翼型反设计方法

 进行了基于扰动放大N-因子的目标压力分布设计方法的多目标自然层流（NLF）翼型反设计方法研究。流场分析和转捩位置计算用XFOIL程序，大大减少了计算花费。用N-因子设计方法进行有NLF范围要求和满足气动约束的目标压力计算，压力恢复段的压力分布用Stratford分离准则来进行设计。用基于响应面方法的优化方法来进行反设计计算，使用不含二阶交叉项的二次多项式模型的响应面模型，大大减少了构造模型所需的试验次数；设计空间内试验点的选取满足D-优化准则。根据设计目标的设计状态，进行了多目标翼型反设计。计算结果表明，设计结果的层流范围和设计目标基本吻合，该方法可以用于NLF翼型的多目标反设计中。

Multi-objective Inverse Design of Natural Laminar Flow Airfoils

A multi-objective inverse design approach of natural laminar flow (NLF) airfoils based on the N-factor method for target pressure distribution is developed. XFOIL code is used to calculate pressure distribution and transition locations to reduce computational cost. It requires special care to design target pressure distribution, and the N-factor design method is used to perform the work with a substantial amount of NLF while maintaining aerodynamic constraints. The pressures in the recovery region are designed according to the Stratford separation criteria. Optimization method based on response surface methodology is used to calculate the target airfoil. Quadratic polynomials are employed to construct the response surface model and the set of candidate design points in design space is selected to satisfy D-optimality. The reduced response surface model without the second-order cross items can greatly reduce computation cost. The design results show that the amount of the NLF satisfies the target requirements, and that the design approach used in the study is applicable to a wide rang of airfoils.