摘要
理解和预测绕椭球的流动对指导飞行器和潜艇等交通工具的设计具有很强的工程意义.近年来,针对椭球绕流开展了大量的实验和数值模拟研究.对有攻角下椭球绕流分离的定性描述和定量研究,促进了对三维分离的辨识和拓扑研究.文章对流场特性进行了分析,介绍了分离对气动力、噪声、尾迹的影响,以及实验条件对流动的影响.上述定常流动与非定常机动过程之间存在明显差异,非定常机动过程不能作为定常或准定常问题处理,在机动过程中,分离出现明显延迟,气动力出现明显变化.随后介绍了数值模拟在求解绕椭球流动中的进展,当前求解雷诺平均的N-S方程湍流模式仍然是解决绕椭球大范围分离流动的主要工程方法,大涡模拟和分离涡模拟等也逐渐得到了广泛应用.受限于计算能力,直接数据模拟只能用于较低雷诺数,在高雷诺数流动中还不适用.非定常机动过程的数值模拟较定常状态,与实验结果的差距要大一些.最后,介绍了对椭球绕流场转捩的研究进展,对T-S转捩与横流转捩的机理和辨识已经较为准确,数值模拟结果与实验结果基本相符,但对再附转捩的认识还不够清晰,尤其是迎风面,因此椭球绕流转捩的研究还需要依靠实验.
Understanding and predicting the flow around the prolate spheroid is of great engineering significance to guide the design of vehicles such as aircraft and submarines.In recent years,a lot of experimental and numerical studies have been carried out on the flow around the prolate spheroid.The qualitative description and quantitative research of flow separation around prolate spheroid at attack angle are presented,promoting the identification and topology research of three-dimensional separation.The experimental results of oil flow,smoke,dye,hydrogen bubble,and LDV are given.The flow field characteristics are analyzed,and the existing problems are pointed out.Based on the introduction of the above phenomena,the effects of separation on aerodynamic force,noise,and wake are introduced.The effects of test conditions such as transition zone,protrusion,depression,and tail support on flow are also discussed.There are obvious differences between the above steady flow and the unsteady maneuvering process.The unsteady maneuvering process can not be treated as a steady or quasi-steady problem.During the maneuvering process,the separation will be delayed obviously,and the aerodynamic force will also change obviously.The greater the angle of attack,the higher the maneuvering rate,the more noticeable this effect will be.At present,RANS turbulence model is still the primary engineering method to solve the largescale separated flow around the prolate spheroid.However,LES,DES,and other methods have gradually been widely used.Due to the limitation of computer capability,DNS can only be used in the case of lower Reynolds number but not in high Reynolds number flow.The difference between the numerical simulation and the unsteady simulation is more significant.Finally,the research progress of prolate spheroid transition is introduced.The mechanism and identification of TS transition and cross-flow transition are more accurate.The numerical simulation results are basically consistent with the experimental results,but the understanding
作者
丛成华
邓小刚
毛枚良
CONG Chenghua;DENG Xiaogang;MAO Meiliang(Key Laboratory of Unsteady Aerodynamics and Flow Control of Ministry of Industry and Information Technology,College of Aerospace Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Facility Design and Instrumentation Institute,China Aerodynamic Research and Development Center,Mianyang 621000,Sichuan,China;Military Academy of Sciences,Beijing 100010,China;Institute of computational aerodynamics,China Aerodynamic Research and Development Center,Mianyang 621000,Sichuan,China)
出处
《力学进展》
EI
CSCD
北大核心
2021年第3期467-619,共153页
Advances in Mechanics
基金
江苏高校优势学科建设工程资助项目。
关键词
椭球
分离
旋涡
尾迹
气动力
噪声
非定常机动
转捩
prolate spheroid
separation
vortex
wake
aerodynamic
sysnoise
unsteady maneuver
transition
