可变后缘弯度机翼柔性蒙皮的变形特性分析

Deformation of Flexible Skin for Variable Trailing-Edge Camber Wing

应用面元法和有限法建立了柔性蒙皮在气动载荷作用下的流固耦合分析方法。数值仿真结果表明:位于变形后缘上表面的柔性蒙皮在气动载荷作用下将被"吸"成鼓包形状,且这个局部变形对翼型后缘部分的压力分布具有很大影响。在此基础上,研究了柔性蒙皮在气动载荷作用下的变形随其弹性模量、厚度和初始预应变的变化规律。可以得出,柔性蒙皮的变形量随着翼型后缘偏角的增加而先增大后减小,并不是随着后缘偏角的增加而增大;增加蒙皮的厚度可以减少柔性蒙皮的最小弹性模量和最小拉伸刚度,但蒙皮的厚度受限于机翼的结构空间;满足Jacobs形变准则的蒙皮最小拉伸刚度随着蒙皮预应变的增加而降低。

The method for calculating the displacement of the flexible skin under the air loads is developed based on the panel method and the finite element method. Numerical results show that the flexible skin on the upper surface of the trailing edge will bubble under the air loads and the bubble has a great effect on the aerodynamic pressure near the surface of the local deformation. Then, the relationships between the deformation of flexible skin and its parameters such as elastic modulus, thickness and prestrain are discussed. It can be seen that the displacement of flexible skin firstly increases and then decreases with the increasing flap angle of trailing edge. To increase the skin thickness can reduce the minimum elastic modulus and the minimum tensile stiffness. But the skin thickness is limited by the space of wing structure. The minimum tensile stiffness based on the Jacobs rules will reduce with the increasing pre-strain acting in the flexible skin.