二维弹性扑翼沉浮运动流动特性的数值研究

采用非定常势流板块法和Euler-Bernoul1i梁振动微分方程,对后缘带弹性薄板的翼型在作沉浮运动时翼型绕流和薄板弹性振动之间的流-固耦合过程进行数值模拟,并计算流动特性、非定常气动载荷,尤其是沉浮运动的推力效应.用有限差分法求解薄板的弹性变形运动,气动弹性分析采用弱耦合迭代方式.通过对翼型非定常气动力(升力和推力)、推进效率、尾迹脱落涡计算结果的分析发现,通过调整弹性薄板的刚度,可以使得翼型产生最佳的非定常推力.

Numerical study of flow characteristics of a plunging rigid airfoil with elastic trailing-edge plate

The fluid-structure coupling process of a plunging rigid airfoil with a thin elastic plate attached at the trailing-edge is simulated numerically by using unsteady potential flow source/vortex panel method and the Euler-Bernoulli beam vibration differential equation.The flow characteristics,the unsteady aerodynamic loads,especially the thrust effects of the plunging motion are computed.The beam vibration differential equation for the elastic deformation motion of the attached trailing-edge plate is solved by finite difference method and the simulation of fluid-structure interaction process is conducted by a loose coupling iterative method.The analysis of the computed unsteady aerodynamic forces(e.g.,lift and thrust),the propulsion efficiency and the shed vortices in the wake reveals that a proper elasticity of the thin elastic plate attached will lead to an optimum thrust for the airfoil.