Di Staso G, Clercx H J H, Succi S, Toschi F
Department of Applied Physics, and J.M. Burgers Centre for Fluid Dynamics, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
Department of Applied Physics, and J.M. Burgers Centre for Fluid Dynamics, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands.
Philos Trans A Math Phys Eng Sci. 2016 Nov 13;374(2080). doi: 10.1098/rsta.2016.0226.
Hybrid particle-continuum computational frameworks permit the simulation of gas flows by locally adjusting the resolution to the degree of non-equilibrium displayed by the flow in different regions of space and time. In this work, we present a new scheme that couples the direct simulation Monte Carlo (DSMC) with the lattice Boltzmann (LB) method in the limit of isothermal flows. The former handles strong non-equilibrium effects, as they typically occur in the vicinity of solid boundaries, whereas the latter is in charge of the bulk flow, where non-equilibrium can be dealt with perturbatively, i.e. according to Navier-Stokes hydrodynamics. The proposed concurrent multiscale method is applied to the dilute gas Couette flow, showing major computational gains when compared with the full DSMC scenarios. In addition, it is shown that the coupling with LB in the bulk flow can speed up the DSMC treatment of the Knudsen layer with respect to the full DSMC case. In other words, LB acts as a DSMC accelerator.This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'.
混合粒子-连续介质计算框架允许通过在空间和时间的不同区域根据流动所显示的非平衡程度局部调整分辨率来模拟气流。在这项工作中，我们提出了一种新方案，该方案在等温流动的极限情况下将直接模拟蒙特卡罗（DSMC）方法与格子玻尔兹曼（LB）方法相结合。前者处理强非平衡效应，因为它们通常出现在固体边界附近，而后者负责整体流动，在整体流动中，非平衡可以用微扰方法处理，即根据纳维-斯托克斯流体动力学来处理。所提出的并发多尺度方法应用于稀薄气体库埃特流，与全DSMC方案相比显示出显著的计算优势。此外，结果表明，在整体流动中与LB耦合相对于全DSMC情况可以加速克努森层的DSMC处理。换句话说，LB起到了DSMC加速器的作用。本文是主题为“物理-化学-生物学界面的多尺度建模”的特刊的一部分。
