摘要
为了获得入水空泡壁面的运动特性与空泡演化之间的关系,进而对入水空泡演化过程开展定量划分研究。采用高速摄像的方法对低弗劳德数条件下的圆柱体入水开展实验研究。通过对比具有水平速度的圆柱体以不同倾角入水空泡,分析了入水空泡壁面运动特性与空泡演化过程的关系,并基于空泡壁面运动特性划分空泡演化各阶段,分析了空泡演化在各阶段的流动机理。实验研究结果表明:空泡壁面的运动特性与空泡演化过程紧密关联,根据空泡壁面位移和运动速度变化规律可定量划分空泡演化阶段。空泡的闭合形式对于具有水平速度的圆柱体入水所形成的空泡的演化过程有显著影响,若空泡发生表面闭合,则空泡演化包含了空泡敞开、空泡体积膨胀、空泡拉长以及溃灭后四个阶段,无量纲分界时间分别为T=2.8、T=5.4和T=6.9;若空泡发生深闭合,则其演化过程仅包含空泡敞开、空泡闭合以及空泡溃灭三个阶段,并以时间T=2.8和T=8.4为分界。根据空泡壁面的运动特性划分空泡演化各阶段的时间特性非常明确且没有相互重叠。
In order to gain the relation between cavity evolution and motion characteristics of cavity wall during a cylinder entry into water,tests for cavity evolution process of a cylinder entry into water with different inclined angles and horizontal velocities under the condition of a lower Froude number were conducted by utilizing a high-speed video camera.Different cavity evolution phases were divided based on motion characteristics of cavity wall,and flow mechanisms were analyzed in various phases of cavity evolution.The test results showed that motion characteristics of cavity wall are closely related to cavity evolution process,different phases of cavity evolution can be quantitatively divided according to change laws of displacement and velocity of cavity wall;cavity evolution process is significantly affected by cavity closure form,if cavity surface is closed,cavity evolution has four phases including cavity opening,its volume-expanding,its stretching and its collapse,respectively,the corresponding dimensionless dividing times are T=2.8,T=5.4,and T=6.9;if cavity is deeply closed,cavity evolution has three phases including cavity opening,its closing and its collapse,respectively,the corresponding dimensionless dividing times are T=2.8 and T=8.4;time features of cavity evolution’s different phases divided according to motion characteristics of cavity wall are very clear and without overlap.
作者
夏维学
王聪
曹伟
李佳川
XIA Weixue;WANG Cong;CAO Wei;LI Jiachuan(School of Astronautics,Harbin Institute of Technology,Harbin 150001,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2020年第15期1-7,17,共8页
Journal of Vibration and Shock
基金
国家自然科学基金(11672094)。
关键词
圆柱体入水
空泡演化
阶段划分
实验研究
cylinder entry into water
cavity evolution
phase-dividing
tests
