大厚度翼型分离流场的稳定性探讨

基于k-ω的SST两方程湍流模型，求解了雷诺平均Navier-Stokes方程获得定常和非定常气动力，耦合翼型弹性振动方程，在时间域内模拟了弹性支撑下的大厚度对称翼型流场及其翼型动态过程，研究结果发现：在所给定的雷诺数条件下，弹性支撑下的大厚度翼型在一定大迎角范围内存在分离流场稳态的转化现象，此结果的意义在于：1）同一基本迎角下的翼型分离涡存在多个稳态流场；2）弹性支撑的翼型在大迎角分离流条件下气动力在物理上本身就存在非唯一性，从一个新的角度解释了大迎角气动力测量中的分散性。

Stability Discussion on Separated Flow Field for Airfoils with Large Thickness at High Incidences

Based on the Reynolds-Averaged Navier-Stokes equations with k-ω SST turbulent model,the steady and unsteady flows are computed. Coupled with the motion equations for an elastic supported airfoil, the unsteady flow- fields of the symmetric airfoil with large thickness are studied in the time domain. It is found that, for the given Reynolds num- bers considered in this paper, the bifurcation of the separation flow- field appears when the airfoils with large thickness at certain range of incidences. These results indicate ： 1 ） multi - stable separation flow- fields exist for the airfoil with large thickness at some large incidences ;2 ）the physical uncertainty exists for elastically supported airfoil with separatio at high incidences, and this may be used to explain the scattered data appearing in engineering aerodynamic measurements.