基于iDDES的双三角翼大迎角非定常涡破裂特征分析

采用基于两方程k-ω-SST模型的iDDES方法对80°/65°双三角翼涡破裂流动进行了数值模拟,获得了迎角α=30°~40°范围内,涡破裂在双三角翼主翼面上方发生时的气动力、表面压力、空间涡结构、湍动能等流动信息,在与风洞实验充分比对的基础上,详细分析了涡破裂发生时的涡破裂形态,表面压力均方根值分布,非定常气动力、表面压力脉动等流动特征,对涡破裂与气动力频谱、表面压力/压力脉动、空间速度、湍动能分布之间的相互关系进行了阐述,并分析了以这些流动信息为判据得到的涡破裂位置之间的相关性。

ANALYSIS ON CHARACTERISTICS OF UNSTEADY VORTEX BREAKDOWN FLOWS AROUND A DOUBLE-DELTA WINGS AT HIGH INCIDENCE BASED ON IDDES METHOD

Numerical investigations were conducted on the vortex breakdown flows around an 80°/65° double delta wings using iDDES (improved-Delayed-Detached-Eddy-Simulation) based on k-ω-SST turbulence model. During vortex breakdown which occurs above the surface of the main wing as the incidence changed from 30° to 40°, flow information including aerodynamic force, pressure on surface and vortex structures was acquired and compared with experiment data adequately. The characteristics of flows during vortex breakdown were analyzed in great detail. Insight was concentrated on the patterns of vortex bursting, distributions of root-mean-square of pressure on the surface, unsteady aerodynamic force and fluctuation of pressure of representative samples. The relationships among the vortex bursting, power-spectral-density of unsteady aerodynamic and pressure samples, root-mean-square of pressure, spatial velocity and turbulent kinetic energy were revealed in depth. The correlations of different criterions about the location of vortex bursting point based on such flow information were depicted and assessed.