中文摘要：

空化泡溃灭对近壁面的冲蚀是流体力学研究中的重点,新兴的格子Boltzmann方法能很好的从底层描述多相流问题.基于格子Boltzmann Shan-Chen模型,耦合了Carnahan-Starling状态方程和可精确得出外力项的精确差分法,利用无滑移反弹边界处理格式和压力边界条件,完整可视化的模拟了二维流场下单气泡在90°刚性壁面拐角处的溃灭泡形演化,并分析了流场内气泡的动力学行为.发现在特定的入口差压和气泡初始半径条件下,在大气泡的压缩过程中90°刚性壁面拐角处可诱导生成新微气泡,生成的新微气泡伴随着大气泡的进一步压缩而溃灭,溃灭释放的反弹压力冲蚀壁面.刚性壁面的阻滞作用对气泡的变形及溃灭影响很大,会减缓气泡的溃灭时间,抑制气泡振动,而且刚性壁面的阻滞效应整体上也是气泡初始半径R0、气泡泡心到刚性壁面的距离b和入口压力差ΔP等共同作用的结果.微气泡的生成表明刚性壁面夹角处的气泡溃灭会产生复杂的涡旋结构,涡旋可促进其他空化泡的形成.流场内涡旋流动特性应是研究空化效应的又一亮点.

英文摘要：

Cavitation bubble erosion to solid walls is a major concern in fluid dynamics.The lattice Boltzmann method（LBM）is especially suitable for describing the complex multiphase flow from the underlying.In this paper,we introduce a model to investigate cavitation bubble collapse on the multiphase LBM.Normally used Shan-Chen model in LBM is modified by coupling with the Carnahan-Starling equation of state（C-S EOS）and exact difference method（EDM）,which is validated as being suitable for simulating high liquid or high vapor density ratio multiphase flows.The feature of this model is that a single equation of state is proposed to describe the cavitation bubble dynamics.The bubble formation and dynamic characters were observed completely and visually in 90°solid corner.From the two dimensional pressure field evolution,dynamics characteristics of the main bubble collapse formation were studied.Meanwhile,a micro-bubble was growing during the collapsing of the main bubble.With the compression process of the main bubble,micro-bubble appeared and expanded to the maximum radius and compressed to collapse finally.However,the main bubble was still in the compressed phase until the final collapse.The generation of micro-bubble shows that bubble collapsing in the rigid wall can produce a complex vortex phenomenon,and vortex structure leads a new cavitation bubble growth.Micro-bubble was closely allied to the main bubble.The retard effect of the rigid wall would make the circular bubble further reduce,and it had a great influence on bubble profiles and collapse phenomenon.The mitigation time of the bubble collapse and bubble oscillation are close to retarding effect.And the whole retarding effect of the rigid wall is due to the initial radius R0,the distance between the rigid wall and bubble centre b and the pressure differenceΔP,those parameters are compete and cooperate.Rigid boundaries with bubble collapse in vortex flow field are important for cavitation research.It is also demonstrated that LBM could be investigated