螺旋桨/大柔性机翼静气动弹性快速分析方法

Aeroelasticity quick analysis method of very propeller / flexible wing system

旋转的螺旋桨滑流掠过机翼将使机翼的气动特性发生改变,在高空超长航时无人机的设计中有必要对大柔性机翼气动弹性问题的螺旋桨滑流影响进行分析.运用Prandtl修正的动量叶素理论分析螺旋桨滑流及面内载荷;采用兰金涡核模拟滑流对机翼的诱导速度;采用三维升力线方法计算机翼定常气动力,利用曲面样条插值方法解决结构/气动耦合问题,并结合非线性有限元静力学计算方法,建立了螺旋桨滑流及面内载荷作用下大柔性机翼静气动弹性问题的快速迭代求解方法.以某大展弦比螺旋桨机翼为例,采用文中所建立方法对其静气动弹性特性进行计算研究.结果表明,旋转的滑流改变了机翼绕流当地攻角,从而影响了机翼气动力和变形分布,且在小前进比时影响更大.所建立的分析方法简便高效,在初步设计阶段有较好的应用前景翼绕流当地攻角,从而影响了机翼气动力和变形分布,且在小前进比时影响更大.所建立的分析方法简便高效,在初步设计阶段有较好的应用前景.

The propeller＇s revolving slipstream passing wing changes the drag / lift property of the wing.For the hyper long endurance unmanned flight vehicles design,the slipstream effect should be analyzed for the aeroelasticity of the very flexible wing. The Prandtl revised blade element-momentum theory was applied to calculate the aerodynamic parameters and in-plane loads（ 1P loads） of the slipstream. Then a Rankine vortex core was placed along the propeller＇s installation axis to simulate slipstream＇s induced effect on the wing.Further,the 3-D lifting-line method was utilized to calculate the steady aerodynamic loads of the curved bending wing. And the generalized surface splines and large deflection interpolation method were adopted to solve the geometrical characters of structure / aerodynamic coupling problem. Coupling with the nonlinear finite element method of the structure,the iterative approach was constructed for the solving of propeller＇s slipstream,1P loads and the static aeroelasticity of very flexible wing. Finally,a validation study of a very flexible rectangular wing with one propeller was carried out using the method constructed. The numerical results show that the revolving slipstream changed the local incidence angle of a wing,thus changing the aerodynamic forces and deformation distribution. And in the small advance ratios situation,it has greater influences. The results demonstrate the applicability of this method in early stages of aircraft design.