面向三维机翼性能的超临界翼型优化设计方法

Aerodynamic optimization method of supercritical airfoil geared to the performance of swept and tapered wing

本文考虑超临界机翼的当地后掠角和当地曲率影响,对带梢根比后掠超临界机翼的二维翼型/三维机翼压力分布的修正转换关系进行了验证,基于此理论发展了面向三维机翼性能的翼型优化设计方法(2.75D方法),并由此获得性能良好的超临界机翼外翼段设计.将此方法的优化设计结果与传统二维转三维设计方法(2.5D方法)以及三维机翼直接优化方法(3D方法)进行了对比.结果表明,相对于传统二维转三维方法,本文的2.75D方法针对当地后掠角和当地曲率进行了修正,可以体现梢根比效应,能够使得二维翼型与三维机翼外翼段相应截面的压力分布形态更加吻合,因此更好地反映三维性能,从而在优化设计中获得三维性能更优的机翼;另一方面,与三维优化设计方法相比,采用2.75D方法进行优化则大大提高了优化效率.

This paper presents an aerodynamic optimization method of supercritical airfoil geared to the performance of a swept and tapered wing based on a revised pressure coefficient transformation equation, which considers the tapered/swept effects and the influence of local swept angle, as well as the local curvature effects of supercritical wing. The airfoil optimized by the present method（2.75 D method） is assembled to the outboard part of a supercritical wing of a wide body civil airplane. An outboard part of supercritical wing with good performance is achieved through this optimization method. The result of optimization design using 2.75 D method is compared with traditional two- to three-dimensional transformation design method（2.5D method） and full three-dimensional optimization design method（3D method）. The comparison results show that, when compared with 2.5D method, because of considering local swept angle and local curvature revision, the 2.75 D method presented in this paper can reflect the tapered effects of three-dimensional wing in airfoil design, and has better agreement between the pressure distribution of airfoil and the corresponding section on the three-dimensional wing, so that better three-dimensional wing will be found in the optimization; on the other hand, when compared with full three-dimensional design method, the presented 2.75 D method will greatly improve the optimization efficiency.