弹性变形对柔性机翼气动特性影响分析

针对大展弦比全复合材料机翼的非线性静气弹响应行为,采用CFD/CSM(Computational Fluid Dynamics/Computational Structural Mechanics)弱耦合方法,使用三维N-S方程和结构力学方程以及动网格生成技术和压强插值技术,通过高精度的数值模拟,求解了大展弦比柔性机翼在结构几何非线性变形状态下的非线性静气弹响应问题.算例分别对典型的大展弦比复合材料前掠机翼和后掠机翼进行了求解,计算结果表明,与前掠翼相比,后掠翼的升力系数明显降低,升阻比降低,严重偏离了刚性机翼的设计点,在柔性机翼的气动设计中必须加以考虑.

Analysis of aerodynamics characteristic of flexible wing caused by deflection

A high-fidelity numerical simulation was presented for the flexible high-aspect ratio composite wing because of its high-speed nonlinear aeroelastic behavior.The fluid-structure interaction procedure used a loosely-coupled methodology.The compressible flow was modeled using the 3-D N-S equations on a deformable mesh,and the computational structural mechanics modeled in a steady analysis with geometrically-nonlinear effects.The transfer of distributed loads and displacements at the fluid-structure interface was based on detailed 3-D representations.Using this approach,a representative high-aspect-ratio composite forward-swept and backwards-swept wing were investigated for the steady flight conditions.Finally,the solution was implemented for the loosely-coupled fluid-structure interaction problem.Compared with the forward-swept wing,the lift coefficient of backwards-swept wing decreases obviously,the lift-drag ratio reduces markedly,which is obviously different from the rigid wing,so it must be considered during the design of a flexible wing.