基于动网格降阶算法的机翼颤振边界预测  

Wing flutter prediction using a reduced dynamic mesh method

作　　者：仲继泽[1] 徐自力[1] 

机构地区：[1]西安交通大学机械结构强度与振动国家重点实验室,西安710049

出　　处：《振动与冲击》2017年第4期185-191,共7页Journal of Vibration and Shock

基　　金：国家自然基金(51275385);国家973(2011CB706505)

摘　　要：基于弹性体动网格技术,发展了一种用于机翼流场网格变形的降阶算法。将流场网格所包围的空间区域视为虚拟弹性体。以虚拟弹性体变形的静力平衡方程为基础,结合机翼的振动控制方程,推导了机翼与虚拟弹性体的整体的振动控制方程。通过模态叠加方法计算机翼和流场网格节点的位移,进而得到变形后的流场网格。考虑到机翼颤振多为1阶弯曲和扭转振动,所以在流场网格节点位移的计算中只需考虑1阶弯曲和扭转振型。为了保证计算精度,在计算中同时考虑了2阶弯曲和扭转振型。RANS方程为流体控制方程,采用Spalart-Allamras湍流模型,结合动网格降阶算法,对AGARD Wing 445.6颤振边界进行了流固耦合计算。计算结果相对于实验值的偏差小于2%,且与已有的弹性体动网格方法比,计算时间减少了54.8%。In this paper, a reduced method for flow mesh deformation around a wing was developed based on the elastic solid method. The flow mesh domain was assumed to be a pseudo elastic solid. The total vibration equation for the wing with the pseudo elastic solid together was derived using the static equilibrium equation of the pseudo elastic solid and the vibration equation of the wing. The nodal displacements for the wing and flow mesh were computed through modal superposition and the deformed flow mesh was obtained. Considering that wing flutter often appeared as the 1st bending and torsion flutter, the nodal displacements for the flow mesh could be calculated by modal superposition of the 1st bending and torsion mode. To ensure the computational accuracy, the 2nd bending and torsion mode were also considered. The flutter boundary of the AGARD Wing 445. 6 was predicted using the present dynamic mesh method coupled with the RANS equations and the Spalart-Allamras turbulent model. The relative error of the calculated results to the experimental data was less than 2% . The computing time was reduced by 54. 8% compared with the pre-existing elastic solid method.

关 键 词：机翼颤振 流固耦合 动网格 虚拟弹性体 模态叠加 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程] O327[理学—一般力学与力学基础]