2018/09/30 by Yanbiao Gan, Yan-Biao Gan, Ai-Guo Xu +9
Engineering · Mathematics · Physics and Astronomy · #Compressibility #Flow (mathematics) #Fluid Dynamics and Turbulent Flows #Gas Dynamics and Kinetic Theory #Instability #Kinetic energy #Lattice Boltzmann Simulation Studies #Mixing (physics) #Non-equilibrium thermodynamics #Thermal conduction #Viscosity #cond-mat.soft
paper · pdf · doi:10.1007/s11467-019-0885-4
published as Front. Phys. 14(4), 43602 (2019) · 37 pages, 15 figures
arxiv created 2019/03/26 · openalex created_date 2019/04/01 · arxiv updated 2019/04/02 · openalex publication_date 2019/04/10 · openalex updated_date 2026/08/05
We investigate the effects of viscosity and heat conduction on the onset and growth of Kelvin–Helmholtz instability (KHI) via an efficient discrete Boltzmann model. Technically, two effective approaches are presented to quantitatively analyze and understand the configurations and kinetic processes. One is to determine the thickness of mixing layers through tracking the distributions and evolutions of the thermodynamic nonequilibrium (TNE) measures; the other is to evaluate the growth rate of KHI from the slopes of morphological functionals. Physically, it is found that the time histories of width of mixing layer, TNE intensity, and boundary length show high correlation and attain their maxima simultaneously. The viscosity effects are twofold, stabilize the KHI, and enhance both the local and global TNE intensities. Contrary to the monotonically inhibiting effects of viscosity, the heat conduction effects firstly refrain then enhance the evolution afterwards. The physical reasons are analyzed and presented.