Viscosity, heat conductivity, and Prandtl number effects in the Rayleigh-Taylor Instability

• Published in: Frontiers of physics Vol. 11; no. 6; pp. 183 - 196
• Main Authors: Chen, Feng, Xu, Ai-Guo, Zhang, Guang-Cai
• Format: Journal Article
• Language: English
• Published: Beijing Higher Education Press 01.12.2016; Springer Nature B.V
• Subjects: Astronomy; Astrophysics and Cosmology; Atomic; Boltzmann; Condensed Matter Physics; Conduction heating; Conductive heat transfer; Conductivity; discrete; discrete Boltzmann model/method; instability,nonequilibrium; Kelvin-Helmholtz instability; model/method; Molecular; multiple-relaxation-time; nonequilibrium; Nonuniformity; Optical and Plasma Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Prandtl number; Rayleigh-Taylor; Rayleigh-Taylor instability; Research Article; Taylor instability; Thermal conductivity; Viscosity; multiple-relaxation-time; discrete Boltzmann model/method; Rayleigh–Taylor instability; nonequilibrium
• ISSN: 2095-0462; 2095-0470
• DOI: 10.1007/s11467-016-0603-4

The two-dimensional Rayleigh-Taylor instability problem is simulated with a multiple-relaxation-timediscrete Boltzmann model with a gravity term. Viscosity, heat conductivity, and Prandtl number ef-fects are probed from macroscopic and nonequilibrium viewpoints. In the macro sense, both viscosityand heat conduction show a significant inhibitory effect in the reacceleration stage, which is mainlyachieved by inhibiting the development of the Kelvin-Helmholtz instability. Before this, the Prandtlnumber effect is not sensitive. Viscosity, heat conductivity, and Prandtl number effects on nonequilib-rium manifestations and the degree of correlation between the nonuniformity and the nonequilibriumstrength in the complex flow are systematically investigated.