Energy dissipation of pulsating bubbles in compressible fluids using the Eulerian finite-element method
Energy dissipation of pulsating bubbles in compressible fluids using the Eulerian finite-element method
复制标题
使用欧拉有限元法可压缩流体中脉动气泡的能量耗散
DOI：
10.1016/j.oceaneng.2019.106714
复制
发表时间：
2020
影响因子：
5
通讯作者：
Longbin Tao
中科院分区：
文献类型：
--
作者：
Zhaoli Tian;Yun Long Liu;Aman Zhang;Longbin Tao
可压缩流体中气泡脉动的能量耗散机制一直是气泡动力学研究的一个重要方面。本文利用欧拉有限元法（EFEM）对可压缩流体中的气泡动力学进行数值研究，并分析了可压缩周围流体的波动效应引起的能量耗散。通过与实验结果的比较验证了本模型的有效性。模拟和实验的结果表明，气泡破碎也会导致能量耗散，这一点以前很少被讨论。研究还表明，初始不连续性对能量耗散具有重要意义，这对于吉尔摩方程等一维气泡动力学方程的模拟来说并非易事。然后，建立耗散能量与相邻脉动循环中气泡最大半径之间的关系，以定量评估脉动循环期间的能量耗散。最后，基于气泡系统能量守恒的线性化理论，从马赫数修正了一个新的无量纲参数M a 来表示波动效应引起的能量耗散。通过对不同初始压力和声速工况的仿真和讨论，发现耗散能量与M a 线性相关，可以用来预测新工况的能量耗散。
Energy dissipation mechanisms of bubble pulsation in compressible fluids have always been a significant aspect of research into bubble dynamics. In this paper, bubble dynamics in compressible fluids are investigated numerically with the Eulerian finite-element method (EFEM), and the energy dissipation due to the wave effects of the compressible surrounding fluid is analyzed. The present model is validated by comparing with experimental results. Results from both the simulation and experiment show that bubble fragmentation also contributes to the energy dissipation, which has seldom been discussed before. It is also shown that the initial discontinuity is significant to the energy dissipation which is non-trivial to simulate in 1-dimensional bubble dynamics equations like the Gilmore equation. Then, the relationship between dissipated energy and bubble maximum radii in adjacent pulsating cycles is formulated to quantitatively evaluate the energy dissipation during a pulsating cycle. At last, based on the linearized theory of the energy conservation of the bubble system, a new non-dimensional parameter M a is modified from the Mach number to represent the energy dissipation due to wave effects. With simulation and discussion on cases with different initial pressure and sound speed, it is found that the dissipated energy is related linearly to M a, which can be used to predict the energy dissipation of a new case.