Chen Jie, Xu Aiguo, Chen Dawei, Zhang Yudong, Chen Zhihua
Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, P.O. Box 8009-26, Beijing 100088, China.
Key Laboratory of Transient Physics, Nanjing University of Science and Technology, Nanjing 210094, China.
Phys Rev E. 2022 Jul;106(1-2):015102. doi: 10.1103/PhysRevE.106.015102.
The two-dimensional Rayleigh-Taylor instability (RTI) in compressible flow with intermolecular interactions is probed via the discrete Boltzmann method. The effects of interfacial tension, viscosity, and heat conduction are investigated. It is found that the influences of interfacial tension on the perturbation amplitude, bubble velocity, and two kinds of entropy production rates all show differences at different stages of RTI evolution. It inhibits the RTI evolution at the bubble acceleration stage, while at the asymptotic velocity stage, it first promotes and then inhibits the RTI evolution. Viscosity and heat conduction inhibit the RTI evolution. Viscosity shows a suppressive effect on the entropy generation rate related to heat flow at the early stage but a first promotive and then suppressive effect on the entropy generation rate related to heat flow at a later stage. Heat conduction shows a promotive effect on the entropy generation rate related to heat flow at an early stage. Still, it offers a first promotive and then suppressive effect on the entropy generation rate related to heat flow at a later stage. By introducing the morphological boundary length, we find that the stage of exponential growth of the interface length with time corresponds to the bubble acceleration stage. The first maximum point of the interface length change rate and the first maximum point of the change rate of the entropy generation rate related to viscous stress can be used as a criterion for RTI to enter the asymptotic velocity stage.
通过离散玻尔兹曼方法研究了具有分子间相互作用的可压缩流中的二维瑞利 - 泰勒不稳定性（RTI）。研究了界面张力、粘度和热传导的影响。结果发现，界面张力对扰动幅度、气泡速度和两种熵产生率的影响在RTI演化的不同阶段均表现出差异。在气泡加速阶段，它抑制RTI演化；而在渐近速度阶段，它先促进然后抑制RTI演化。粘度和热传导抑制RTI演化。粘度在早期对与热流相关的熵产生率表现出抑制作用，但在后期对与热流相关的熵产生率表现出先促进后抑制的作用。热传导在早期对与热流相关的熵产生率表现出促进作用。不过，在后期它对与热流相关的熵产生率也表现出先促进后抑制的作用。通过引入形态边界长度，我们发现界面长度随时间呈指数增长的阶段对应于气泡加速阶段。界面长度变化率的第一个最大值点以及与粘性应力相关的熵产生率变化率的第一个最大值点可作为RTI进入渐近速度阶段的判据。
