融合体布局超临界翼型设计研究

摘要

针对跨声速融合体布局飞机,构建了所需超临界翼型的气动优化设计问题;基于"人在回路"的多轮迭代优化理念建立了翼型多目标多约束优化设计平台,其中:翼型参数化采用基于型函数/类函数变换的参数化方法,气动力解算器采用基于三维雷诺平均Navier-Stokes方程(RANS)的求解程序CCFD-MB,计算网格生成与网格更新采用基于无限插值和椭圆光滑算法的C型结构网格程序,优化算法采用多目标优化遗传算法NSGA-II.设计结果显示,优化翼型具有常规超临界翼型的基本气动力特征,满足阻力发散、抖振边界和低速特性要求;同时具有前加载特征,低头力矩大幅低于常规超临界翼型,满足融合体布局气动力要求.%Based on the aerodynamic characteristics of blended wing body configuration, an analysis is carried out on aerodynamic design requirements for a required super critical airfoil, and problems are extracted for the airfoil design of transonic blended wing body. A multi-target multi-constraint optimization design platform for super critical airfoil of belnded wing body is established on the basis of the concept of multi-iteration optimization. In this platform, class function /shape function transformation method is used for the airfoil parameterization, and the CCFD-MB based on three-dimensional Reynolds average Navier-Stokes equations (RANS) is used to solve aerodynamic force. For the computation grid and grid update, c-structured grid is used together with transfinite interpolation method(TFI)and elliptic equationsmoothing algorithm. Non-dominated sorting genetic algorithm II (NSGA-II) is adopted as the present optimization algorithm. It is found that the optimized airfoil has the capabilities of possessing basic aerodynamic characteristics of traditional super critical airfoil and satisfying the requirements for drag divergence, vibration boundary, and low-speed characteristics. Moreover, this optimized airfoil has characteristics of front loading, significantly higher pitch moment coefficient compared with that of traditional super critical airfoil, and satisfying the aerodynamic requirements for an aircraft with belnded wing body configuration.