Coupled Navier-Stokes/DSMC Method for Transient and Steady-State Gas Flows

Abstract

Abstract. An adaptatively coupled continuum-DSMC approach for compressible, viscous gas flows has been developed. The continuum domain is described by the unsteady Navier-Stokes equations, solved using a finite volume formulation in compressible form to capture the shock. The molecular domain is solved by the Direct Simulation Monte Carlo method (DSMC). The coupling procedure is an overlapped Schwarz method with Dirichlet-Dirichlet boundary conditions. The domains are determined automatically by computing the Kn number with respect to the local gradients length scale. The method has been applied to simulate a 1-D shock tube problem and a 2-D expanding jet in a low pressure chamber.

Multi-scale Modelling of the Two-Dimensional Flow Dynamics in a Stationary Supersonic Hot Gas Expansion

“…The present method has been described in detail in [12,13] and validated in [14], here only a short description will be given.…”

“…The method has been found to be rather insensitive to the precise CFD/DSMC interface location w.r.t. Kn split [12].…”

“…The present hybrid method has been presented in [12,13] and validated in [14]. The method applies the continuum approach in the wide continuum region in order to save computational time and to get numerical simulations of the flow, pressure and temperature of the expanding jet at large scales.…”

Simulation of Multiphysics Multiscale Systems: Introduction to the ICCS’2007 Workshop

“…The first one is the development of sophisticated models for each physical process, characterized by its own specific scales and its own mechanisms, and integration of these models into one seamless simulation. Coupling or extension of atomistic and continuum models studied in [8][9][10][11][12][13][14] shows that sophisticated modeling is essential to accurately represent the physical world. Similarly, works in [15][16][17][18] demonstrate that biological or biomedical systems have intrinsically multiscale nature and require multiscale modeling.…”

“…The projects in [8][9][10] investigate computationally efficient yet physically meaningful ways of coupling discrete and continuum models across multiple scales. Another way of treating multiscale problems is to develop single-scale approximation models.…”