3D full coupling model for strong interaction between a pulsating bubble and a movable sphere
3D full coupling model for strong interaction between a pulsating bubble and a movable sphere
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脉动气泡与可移动球体之间强相互作用的 3D 全耦合模型
DOI：
10.1016/j.jcp.2019.05.001
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发表时间：
2019-09-01
影响因子：
4.1
通讯作者：
Ma, Qingwei
中科院分区：
文献类型：
--
作者：
Li, Shuai;Zhang, A-Man;Ma, Qingwei
在这项研究中，我们建立了一个完整的耦合模型（FCM），以模拟基于三维边界积分方法的强气泡 - 球相互作用。与常规的松散耦合模型（LCM）不同，FCM采用了几种辅助功能来应对流体动力和球体加速度之间的相互依赖性。此外，还实施了加权运动最小平方法，网格密度控制方案和自适应网状细化方案，以提高可变形气泡表面网格的质量。为了验证当前的模型，首先对不同的网格尺寸和时间步骤进行收敛测试。还将数值结果与轴对称模型进行了比较，该模型已实现了一致的结果。我们进一步比较数值结果与不同边界条件下的几个实验的结果之间的比较。对于弱相互作用情况，LCM和FCM都可以给出与实验数据有良好一致的结果。随着相互作用的效果变得更强，FCM比LCM的优势变得越来越明显。特别是，当脉动气泡与球体表面接触时，FCM可以很好地再现实验的基本物理特征，而LCM的预测与实验明显不同。目前的3D模型可以进一步扩展，以研究更复杂的水下接触爆炸，结构和气枪气泡动力学的空化开始。 （c）2019 Elsevier Inc.保留所有权利。
In this study, we establish a full coupling model (FCM) to simulate strong bubble-sphere interactions based on a three-dimensional boundary integral method. Different from the conventional loose coupling model (LCM), FCM adopts several auxiliary functions to deal with the mutual dependence between the hydrodynamic force and the sphere acceleration. In addition, the weighted moving least square method, a mesh density control scheme and an adaptive mesh refinement scheme are implemented to improve the quality of mesh on the deformable bubble surface. To validate the present model, convergence tests on different mesh sizes and time steps are conducted at first. The numerical results are also compared with the axisymmetric model, in which consistent results have been achieved. We further make comparisons between the numerical results and those from several experiments under different boundary conditions. For weak interaction cases, both LCM and FCM can give the results that have good agreement with the experiment data. As the interaction effects become stronger, the advantage of the FCM over the LCM becomes increasingly obvious. Particularly, when the pulsating bubble is in contact with the sphere surface, the essential physical features of the experiments can be well reproduced by the FCM while the predictions by the LCM are significantly different from the experiment. The present 3D model can be further extended to study more complex underwater contact explosions, cavitation inception on a structure and airgun bubble dynamics. (C) 2019 Elsevier Inc. All rights reserved.