鱼骨柔性翼段线性/非线性静气动弹性对比分析

鱼骨柔性翼作为一种性能优越的主动变弯度机翼机构形式，具有弦向抗弯刚度低、翼型厚度方向刚度高的特点，其在进行大弯度主动变形时结构存在较强的几何非线性且气动弹性效应显著。针对传统线性静气动弹性分析方法并不适用于鱼骨柔性翼段的气动弹性分析问题，以Bristol大学的公开鱼骨柔性翼段模型为研究对象，采用曲面涡格法（VLM）和非线性有限元耦合的非线性静气动弹性方法，以及传统气动弹性分析中常用的平面涡格法和线性有限元耦合的线性静气动弹性方法，分别对鱼骨柔性翼段进行大变形下的静气动弹性分析，并进行结果对比。对比验证了所用曲面涡格法与XFOIL软件气动计算结果。算例结果表明:鱼骨柔性翼段大变形下气动弹性效应显著，相比传统线性静气动弹性分析方法，非线性静气动弹性分析方法得到的鱼骨柔性翼段在大变形状态下升力系数最多减少8.28%，力矩系数最多减少6.86%，且能准确快速得到真实变形结果，更具有实际工程应用价值。 

Comparative analysis of linear/nonlinear static aeroelasticity of fishbone flexible wing

Fishbone flexible wing is a excellent design of active morphing camber wing. Ithas low chordwise bending stiffness and high stiffness along the thickness direction of airfoil, and it has strong geometric nonlinearity and significant aeroelastic effect when undergoing active deformation with large deformation. The traditional linear static aeroelastic analysis method is not fit for this problem. Therefore, this paper takes the public fishbone flexible wing model of Bristol University as the research object, adopts the nonlinear aeroelastic analysis method which is based on non-planar Vortex Lattice Method (VLM) and nonlinear finite element analysis and the traditional linear aeroelastic analysis method which is based on linear finite element analysis and planar VLM to analyze the static aeroelasticity of the fishbone wing under large deformation and compare the results. Similarly, the aerodynamic calculation results of the non-planar VLM and XFOIL software used in this paper are verified. The results show that the aeroelastic effect of the fishbone flexible wing under large deformation is significant. Compared to the results of traditional linear static aeroelasticity analysis method, the lift coefficient of fishbone wing under large deformation by nonlinear static aeroelasticity analysis method is 8.28% smaller at most, and the moment coefficient is 6.86% smaller at most. The real deformation under the aerodynamic load can be obtained accurately and quickly by the nonlinear aeroelasticity analysis method proposed in this paper, which is more valuable for practical engineering application.