格子Boltzmann方法模拟空化泡溃灭和微气泡的初生

发布时间：2018-03-23 13:04

本文选题：格子Boltzmann方法　切入点：°刚性壁面　出处：《南京大学学报(自然科学)》2017年01期

【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.
[Abstract]:The erosion of cavitation bubble collapse to the near wall is the focus of hydrodynamics research. The new lattice Boltzmann method can describe the multiphase flow problem from the bottom layer very well. Based on the lattice Boltzmann Shan-Chen model, the new lattice Boltzmann method can describe the multiphase flow problem from the bottom layer. The Carnahan-Starling equation of state is coupled with the exact difference method which can accurately obtain the external force term. The non-slip bouncing boundary treatment scheme and the pressure boundary condition are used. The evolution of bubble collapse at the corner of 90 掳rigid wall in two-dimensional flow field is simulated visually, and the dynamic behavior of bubble in the flow field is analyzed. It is found that under certain conditions of inlet differential pressure and initial radius of bubble, A new micro bubble can be induced to form at the corner of 90 掳rigid wall during the compression of a large bubble, and the new bubble collapses with the further compression of the large bubble. The rebound pressure released by collapse erodes the wall surface. The blocking effect of rigid wall has a great effect on the bubble deformation and collapse, which will slow down the bubble collapse time and suppress the bubble vibration. Moreover, the blocking effect of rigid wall is also the result of the initial radius of bubble R0, the distance from the bubble center to the rigid wall b and the inlet pressure difference 螖 P. the formation of micro bubble indicates that the bubble at the angle between rigid wall and so on. Collapsing produces complex vortex structures, Vortex can promote the formation of other cavitation bubbles, and the vortex flow characteristics in the flow field should be another bright spot in the study of cavitation effect.
【作者单位】：陕西师范大学物理学与信息技术学院陕西省超声学重点实验室;
【基金】：国家自然科学基金(11674207;11174191)
【分类号】：O35

【相似文献】