Lattice Boltzmann simulation of cavitating bubble growth with large density ratio
Lattice Boltzmann simulation of cavitating bubble growth with large density ratio
复制标题
大密度比空泡生长的格子玻尔兹曼模拟
DOI：
10.1016/j.camwa.2010.07.018
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发表时间：
2011-06-01
影响因子：
2.9
通讯作者：
Yuan, Xu-Long
中科院分区：
文献类型：
--
作者：
Chen, Xiao-Peng;Zhong, Cheng-Wen;Yuan, Xu-Long
自然空化被定义为由于压力下降到低于液体的蒸气压而在流中形成蒸气泡。空化泡的形成受杂质、湍流、液体热物性等多方面因素的影响。本文将精确差分法（EDM）与Carnahan-Starling真实气体状态方程（EOS）耦合应用于Shan-Chen多相格子Boltzmann模型，验证了该模型适用于模拟高液汽密度比多相流。在初始阶段，模拟了静止流和剪切流条件下二维空化泡的生长过程。真实气体状态方程除了产生较大的密度比外，还导致了液体和蒸汽的压缩系数明显不同。结果与Rayleigh-Plesset预测的一致性比文献[X. Chen，Simulation of 2D cavitation bubble growth under shear flow by lattice Boltzmann model，Communications in Computational Physics 7（2010）212-223]。同时，比较了不同剪切速率下的单气泡行为，折合温度T/T（临界）= 0.6891和松弛时间τ = 1.0。模拟结果表明，空泡变形与空泡动力学规律一致，D与Ca成正比，其中D和Ca分别为空泡变形和毛细数。剪切速率几乎不影响气泡的生长速率。(C)2010爱思唯尔有限公司版权所有。
Natural cavitation is defined as the formation of vapor bubbles in a flow due to the pressure falling below the liquid's vapor pressure. The inception of the cavitation bubble is influenced by a lot of aspects, such as impurities, turbulence, liquid thermal properties, etc. In this paper, the exact difference method (EDM) and the Carnahan-Starling real-gas equation of state (EOS) are coupled in the Shan-Chen multiphase lattice Boltzmann model, which is validated as being suitable for simulating high liquid/vapor density ratio multiphase flows. The 2D cavitation "bubble" growth is simulated under a quiescent and shear flow in the inception stage. Besides yielding the large density ratio, the real-gas EOS also leads to apparently different compressibilities for liquid and vapor. The results agree with Rayleigh-Plesset predictions much better than those of a previous publication [X. Chen, Simulation of 2D cavitation bubble growth under shear flow by lattice Boltzmann model, Communications in Computational Physics 7 (2010) 212-223]. In the meantime, a comparison is conducted for single-bubble behavior under different shear rates, with reduced temperature T/T(critical) = 0.6891 and relaxation time tau = 1.0. The simulation results show that the cavitation bubble deformation is consistent with the bubble dynamics, D proportional to Ca, where D and Ca are the bubble deformation and the capillary number respectively. The shear rate hardly influences the bubble growth rate. (C) 2010 Elsevier Ltd. All rights reserved.