基于预变形设计的柔性机翼气动性能分析

Analysis of Aerodynamics Characteristic of Flexible Wing on Pre- deformation

大展弦比复合材料机翼在大量减轻机体重量的同时,也极大地增加了机翼的柔性,对飞机的气动特性和安全性构成了不利影响。针对大展弦比复合材料机翼的气动变形行为,应用有限元及流固耦合计算方法,在计算、分析机翼刚心轴线随机翼柔性变形而产生的位移的基础上,提出了复合材料机翼的预变形设计分析方法,并就预变形机翼变形前后的气动性能与理想刚性机翼进行了对比分析。计算结果表明,在巡航状态下,预变形机翼能够在有效提升机翼升阻比的情况下,保证机翼的升阻比特性与设计要求相符,但在非巡航状态下,随着飞行速度的改变,预变形机翼的升阻比将有所下降。因此,预变形设计的适用对象应为长期处于巡航状态的飞机。

The flexibility of high -ratio -aspect composite wing was greatly increased while the weight lowering largely, which caused negative effects on the aerodynamic characteristics and safety of the aircraft. Aiming at the aerodynamic deformation of the high - ratio -aspect composite wing, a pre -deformation method was proposed by using the finite element method and the fluid structure coupling method to calculate the displacement of stiffness - center axis along with the flexure deformation of the wing. Then compared the aero- dynamic performance of the pre - deformed wing which after and before the deformation. The calculation results showed that the pre - deformed wing could effectively promote the lift - to - drag ratio and ensure the lift - to - drag ratio characteristic of the wing consistent with the design requirement. However, the lift - to - drag ratio would decrease with the variation of the flight velocity while non - crui- sing, which indicated that the pre - deformation method could be used on the aircraft cruising long - term.