title: Lattice Boltzmann accelerated direct simulation Monte Carlo for dilute gas flow simulations.
abstract: 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'.
authors.affiliation: Department of Applied Physics, and J.M. Burgers Centre for Fluid Dynamics, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands g.di.staso@tue.nl.
authors.forename: G
authors.identifier: http://orcid.org/0000-0002-8247-5776
authors.initials: G
authors.lastname: Di Staso
authors.affiliation: Department of Applied Physics, and J.M. Burgers Centre for Fluid Dynamics, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands.
authors.forename: H J H
authors.initials: HJ
authors.lastname: Clercx
authors.affiliation: Istituto per le Applicazioni del Calcolo, Consiglio Nazionale delle Ricerche, Via dei Taurini 19, 00185 Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Succi
authors.affiliation: Department of Applied Physics, and J.M. Burgers Centre for Fluid Dynamics, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands Istituto per le Applicazioni del Calcolo, Consiglio Nazionale delle Ricerche, Via dei Taurini 19, 00185 Rome, Italy Department of Mathematics and Computer Science, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Toschi
keywords: Monte Carlo method; hybrid model; kinetic theory; lattice Boltzmann method; non-equilibrium effects