基于正交分解技术的汽车非定常流场分析及重构  

Analysis and reconstruction of unsteady flow field around automobile based on POD technology

作　　者：王国俊[1] 崔文诗[1] 周华[1] 朱晖[1] 杨志刚[1] 

机构地区：[1]同济大学上海地面交通工具风洞中心,上海201804

出　　处：《计算机辅助工程》2016年第4期33-39,共7页Computer Aided Engineering

摘　　要：为有效开展汽车气动优化设计和主动流动控制技术,采用正交分解(Proper Orthogonal Decomposition,POD)技术分析汽车非定常流场中POD模态的物理意义,并利用重构技术建立汽车外流场瞬态简化模型.大涡模拟(Large Eddy Simulation,LES)仿真结果与实验结果的对比表明该仿真方法有效.POD分析结果表明:低阶模态主要对应分离泡的附着流动,包含流场中较高的能量;其他各个高阶模态含能相对较低,表征小尺度涡的作用.当保留前15阶POD模态时,通过重构技术可获得70%的原流场能量,得到的降阶模型可以较好地捕捉流动的特征.To carry out the automobile aerodynamic optimization design and the active flow-control technology effectively, the Proper Orthogonal Decomposition （ POD） technology is used to analyze the physical meaning of POD modes in unsteady flow field around automobile, and a simplified transient model is built for flow field of automobile outer flow field. The Large Eddy Simulation（ LES） results are compared with the experimental results to verify that the simulation method is effective. The POD analysis results show that, the low-order modes correspond to the attached flow of separation bubbles, which contains high energy of the flow field. Other high-order modes contain relatively low energy, which represents the effect of small scale vortex. If the first 15 order POD modes are retained, 7 0 % energy of the original flow field can be obtained through reconstuction technology, the low-dimensional model can well capture the characteristics of the flow.

关 键 词：汽车 非定常流场 正交分解 大涡模拟 简化模型 Ahmedbody 流场重构 涡能量耗散 

分 类 号：U461.1[机械工程—车辆工程]