基于本征正交分解的脉冲射流尾迹分析  

Wake analysis of pulsed jet based on proper orthogonal decomposition

作　　者：陈款 张艳华[2] 雷玉昌 卢昂 张登成[2] CHEN Kuan;ZHANG Yanhua;LEI Yuchang;LU Ang;ZHANG Dengcheng(Graduate School,Air Force Engineering University,710051 Xi'an,China;Aeronautics Engineering College,Air Force Engineering University,710038 Xi'an,China;95034 Troops of the PLA,533601 Baise,China)

机构地区：[1]空军工程大学研究生院,西安710051 [2]空军工程大学航空工程学院,西安710038 [3]中国人民解放军95034部队,百色533601

出　　处：《应用力学学报》2022年第5期834-844,共11页Chinese Journal of Applied Mechanics

摘　　要：基于雷诺平均N-S方程对脉冲射流作用下的翼型非定常流场进行数值模拟,采用本征正交分解(POD)方法对低频率、中等频率、高频率脉冲射流尾迹中涡结构的变化进行分析。结果表明:借助POD方法能够有效提取尾迹中小尺度涡结构的运动状态。POD方法提取的低阶模态主要反映了尾迹中强度最大的尾涡静态分离结构,对应脉冲射流的主频成分,高阶模态则主要反映了尾涡内部或尾涡之间的流动状态,对应脉冲射流的高阶倍频成分,尾涡内部的相互拉伸包含频率范围较广,尾涡之间的牵引分解包含频率较为单一;低频率下尾迹中仅能提取到一对主要尾涡,高频率下尾迹中能提取到多对强度相当的尾涡;低频率下尾涡单一且相互作用简单,用前六阶模态即可表征流场结构,高频率下尾涡数量多且相互作用复杂,需要更高阶模态才能表征其流场结构。The unsteady flow field of an airfoil under the action of pulsed jet is numerically simulated based on the Reynolds average N-S equation.The proper orthogonal decomposition(POD)method is used to analyze the variation of small-scale vortex structure in the wake of low-frequency,medium-frequency,and high-frequency pulsed jet.The results show that with the help of the POD method,the motion state of the wake small-scale vortex structure can be effectively extracted.The low-order modes extracted by the POD method mainly reflect the static separation structure of the wake vortex with the greatest intensity in the wake,corresponding to the main frequency component of the pulsed jet.The higher-order modes mainly reflect the flow state inside or between the wake vortices,corresponding to the high-order frequency doubling components of the pulsed jet.The mutual stretching within the wake vortex contains a wide range of frequencies,and the traction decomposition between the wake vortices contains a single frequency.Only a pair of main wake vortices can be extracted from the wake at low frequency,and many pairs of wake vorti ces with the same intensity can be extracted from the wake at high frequency.At low frequency,the wake vortex is single and the interaction is simple.The first six modes can be used to characterize the flow field structure.At high frequency,the number of wake vortices is large and the interaction is complex,so higher order modes are needed to characterize the flow field structure.

关 键 词：脉冲射流 本征正交分解 尾迹 小尺度涡 数值模拟 

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]