自由曲线翼梢小翼设计及涡格法应用

The Design of Winglet Based on Freestyle Curve with VLM

翼梢小翼具有减少诱导阻力的作用,加装小翼对于运输机而言可以提高气动性能。传统翼梢小翼设计理念类似于机翼设计方法,外形变化主要集中于几个主要的几何参数。CATIA中的自由曲线(NURBS)在多参数控制下具有很强的成形能力,这就可以用于小翼设计。研究基于自由曲线建模方法的翼梢小翼的优化设计问题,利用涡格法程序,以阻力最小为目标,探索全局优化下的结果;同时研究了主要参数对小翼阻力和翼根弯矩的影响。结果表明,采用自由曲线方法构造的参数化小翼经过优化之后能够取得良好的减阻效果;涡格法能够在多参数情况下发挥计算效率高的特点;涡格法通过参数约束可以获得良好的优化结果。

The application of winglet on transport will lead to improvement of aerodynamic characteristics for that it is able to reduce the induced drag ofwing. Freestyle curves(NURBS) in CATIA can establish various forms of curve controlled by many suitable geometry parameters within a reasonablerange, therefore it can be used to design a winglet which is different from the one designed by a traditional method. The winglet designed has goodperformance on drag reduction using the Vortex Lattice Method (VLM) in global range. In addition, the impact of height on drag reduction was studiedaccording to the results of a large amount of winglets. It was found that VLM is suitable for a model with many parameters due to its high computationalefficiency.It was indicated that an optimal design with VLM is able to obtain good results.