Linear wave propagation of fast and slow modes in mixtures of liquid and gas bubbles
Linear wave propagation of fast and slow modes in mixtures of liquid and gas bubbles
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DOI：
10.1016/j.fluiddyn.2004.02.004
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发表时间：
2004-05-01
影响因子：
1.5
通讯作者：
Fujikawa, S
中科院分区：
文献类型：
--
作者：
Egashira, R;Yano, T;Fujikawa, S
导出了一组新的描述气液混合气泡动力学的空间平均方程，其中气液界面的表面平均液体压力和体积平均压力作为变量，并考虑了液体的可压缩性。为了验证模型方程的有效性，对线性平面波在静止混合物中的传播进行了理论和数值研究。结果表明，对于所有的实数波数，液体的可压缩性导致了两种传播模式，一种是快模式，一种是慢模式，如果假设液体是不可压缩的，则只存在慢模式。由于以往的研究多采用不可压缩性近似来描述液体相，因此对快速模式的研究还不够深入。在本研究中，阐明了慢模式和快模式的几个重要特征。特别指出，快模式的幅值并不总是很小，当一个典型波数超过某一临界值时，它可能变大。(C)2004年，由日本流体力学学会和爱思唯尔出版。版权所有。
A new set of space-averaged equations that governs the dynamics of mixtures of liquid and gas bubbles is derived, where a surface-averaged liquid pressure at the gas-liquid interface is used as a variable as well as volume-averaged pressures, and the liquid compressibility is taken into account. To verify the validity of the model equations, the propagation of linear plane wave in a quiescent mixture is studied theoretically and numerically. It is shown that the compressibility of liquid induces two propagation modes, a fast mode and a slow mode, for all real wave numbers, and if one assumes that the liquid is incompressible there only exists the slow mode. Since the incompressibility approximation has been used for liquid phase in previous studies, the fast mode has not been investigated in detail. In the present study, several important characters of the slow and fast modes are clarified. In particular, it is demonstrated that the amplitude of the fast mode is not always small and it can become large when a typical wave number exceeds a critical value. (C) 2004 Published by The Japan Society of Fluid Mechanics and Elsevier B.V. All rights reserved.