为研究高速射弹在海水里不同速度下的出水过程中空泡形态和弹体运动变化规律,采用了Fluent中的VOF模型,并结合Schnerr and Sauer空化模型,同时运用了动网格技术和三维6自由度方法,对射弹在海水中的射出过程进行了数值模拟。结果发现:弹...为研究高速射弹在海水里不同速度下的出水过程中空泡形态和弹体运动变化规律,采用了Fluent中的VOF模型,并结合Schnerr and Sauer空化模型,同时运用了动网格技术和三维6自由度方法,对射弹在海水中的射出过程进行了数值模拟。结果发现:弹体在从海水射出过程中,形成包裹弹体的超空泡会被拉长,可以通过控制弹体初始速度的大小,以影响超空泡的形成和尺寸。水下弹体运动的初始时刻,阻力系数最大,达到峰值。初始速度越大,在水中产生的压力峰值越大,并且压力和速度衰减得越快;但初始速度过大,弹体在水中所受到的压力越不稳定,因此需要选择合适的速度以避免弹体在出水过程中受到过大的不稳定压力影响。展开更多
In this short paper the following viewpoints are discussed: it is possible in super high dams that the discharge flow, either in discharge tunnel or in open channel, may be an air water mixtures (two phase flow) in ...In this short paper the following viewpoints are discussed: it is possible in super high dams that the discharge flow, either in discharge tunnel or in open channel, may be an air water mixtures (two phase flow) in which the sound speed could reduce sharply depending on concentration of air, and the shock wave could be caused somewhere in super high flow while the flow velocity reaches or exceeds the sound speed in it. Besides bubble collapse, the correlation between shock wave and cavitation bubble collapse should be considered as the main mechanism of serious damage on discharge structures of super high dams.展开更多
文摘为研究高速射弹在海水里不同速度下的出水过程中空泡形态和弹体运动变化规律,采用了Fluent中的VOF模型,并结合Schnerr and Sauer空化模型,同时运用了动网格技术和三维6自由度方法,对射弹在海水中的射出过程进行了数值模拟。结果发现:弹体在从海水射出过程中,形成包裹弹体的超空泡会被拉长,可以通过控制弹体初始速度的大小,以影响超空泡的形成和尺寸。水下弹体运动的初始时刻,阻力系数最大,达到峰值。初始速度越大,在水中产生的压力峰值越大,并且压力和速度衰减得越快;但初始速度过大,弹体在水中所受到的压力越不稳定,因此需要选择合适的速度以避免弹体在出水过程中受到过大的不稳定压力影响。
基金Project supported by the National Natural Science Foundation of China.(No.59479009)
文摘In this short paper the following viewpoints are discussed: it is possible in super high dams that the discharge flow, either in discharge tunnel or in open channel, may be an air water mixtures (two phase flow) in which the sound speed could reduce sharply depending on concentration of air, and the shock wave could be caused somewhere in super high flow while the flow velocity reaches or exceeds the sound speed in it. Besides bubble collapse, the correlation between shock wave and cavitation bubble collapse should be considered as the main mechanism of serious damage on discharge structures of super high dams.