Group of Impact Dynamics and Coupling Effects

Our lab addresses a variety of topics in the general area of mechanics of materials and structures coupled with its working or processing environments, which include the interaction between the structure and fluid, the interaction between the structure and thermal field, and the interaction between the materials and shock loading. The overarching goal is the solution of technological problems through the integration of analytical, computational and experimental techniques. Depending on the specific problem at hand, we study and apply concepts and methods of solid mechanics, fluid mechanics, heat transfer and materials sciences.

 


Chenguang HUANG
Research Fellow
Deputy Director

Room 2-306
Key Laboratory for Mechanics in Fluid Solid Coupling Systems (LMFS)
Instituteof Mechanics(IM)
ChineseAcademyof Science (CAS)
No.15 Beisihuan West Road
BeijingPRC 100190
Tel: 86-10-8254-3879  
Fax: 86-10-8254-4256
E-mail: huangcg@imech.ac.cn
Web:People in LMFS, CAS

Hongwei SONG
Professor


 


Yiwei WANG
Associate Professor

Yanpeng WEI
Associate Professor


Lijuan LIAO
Associate Professor


Tezhuan DU
Assistant Professor


Xianqian WU
Assistant Professor


Xiaocui WU
Assistant Professor

 

 

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力学所在高速航行体水动力学载荷研究方面取得进展
作者:王一伟

      航行体在水下高速运动过程中,表面低压区的压力低于饱和蒸汽压时,液态水会相变为水蒸气,形成水汽混合的空泡。云状空泡是在航行体高速水动力学领域中最重要的空泡表现形态之一。云状空泡的非定常、周期性演化特性能够诱导产生航行体的载荷波动,其衍生的空泡稳定性问题非常具有挑战性。

      在航行体出水等条件下,空泡周围压力升高到一定程度,泡内水蒸气凝结为液态水,引起空泡剧烈收缩并伴随很高的冲击压力,这就是空化的逆过程-溃灭。航行体高速水动力学问题中,通常表现为空泡群的溃灭行为。群体溃灭的累积效应,能够形成较大面积、较长脉宽的压力脉冲。溃灭冲击与结构振动发生耦合,往往会直接危害结构的完整性,其特征和机理是高速水动力学相关问题的重要研究对象。

      前期工作中,力学所建立了水下发射水动力学与多体动力学仿真方法,率先基于流固耦合技术形成了水下发射全过程载荷仿真平台;研发了水平和垂直水下发射机理性实验系统,基于不同尺度实验完成了数值模拟方法的验证;建立了回射流动力学模型,揭示了自然云状空泡不稳定性机制,形成了空泡脱落条件准则;提出了出水溃灭压力物理模型,探索了溃灭与结构振动耦合作用机制,澄清了此前采用的溃灭压力的相似条件中的问题;研究了通气对空泡稳定性和溃灭的影响机理,得到了通气空泡脱落这一新现象的特征和机制,预示了通气的良好效果;上述工作为有关工程提供了及时的支撑。

      2014年6月13日,郑哲敏院士应邀以“水下发射高速水动力学问题研究”为题,就相关研究工作在中国科学院第十七次院士大会数学物理学部第四届学术报告会上进行报告交流。

      相关工作已发表于Journal of Fluids Engineering - Transactions of ASME, Ocean Engineering, Chinese Physics Letters,《力学学报》等刊物上。上述研究工作得到了中国科学院知识创新工程重要方向项目“结构水动力载荷及其动力学响应特征研究”等计划的支持,由黄晨光研究员等主持完成并已在日前通过验收。

LMFS供稿 


Hydrodynamics & Fluid-Structure Coupling area, which orients to analysis and solve the problems of mechanics of fluid-structure coupling system in the applications of the national key engineering projects, seeks to clarify the mechanisms, provide the design guideline and guarantee the safety in fluid-structure coupling systems in practical engineering. The main researches are mainly including:
    •     Unsteadycavitating flow mechanism
    •     Mechanism and dynamic loadings of collapse of cavitation bubbles around the high-speed underwater vehicle in the out-of-water process
    •     Fluid-structurecoupling of high-speed vehicle during underwater launching process
    •     Maneuverability of new pattern vehicles in the underwater and surface navigation conditions
    •     Fluid-structure coupling of the large-scale flexible airship.

 

This platform dedicates to the research of some transient energy transformation process (high-speed deformation of material, laser shock peening and explosive underwater etc.). The high density laser is used as the driven sources which can generated a very high amplitude (up to 5 GPa) pressure pulses in very short time (about 20 ns). A variety of high spatial and temporal resolution test method including PVDF (Polyvinylidene Fluoride), PDV (Photonic Doppler Velocimetry) and high-speed camera etc is adopted to capture the transient process. The main experimental system includes:
•  Laser shock peening system
•  Dynamic material property system
•  Underwater explosive system