Lockerby, Duncan A., Duque-Daza, Carlos A., Borg, Matthew K. and Reese, Jason M. (2012) Efficient time-Step coupling For hybrid continuum/molecular modelling of unsteady micro-Scale gas flows. In: 1st European Conference on Gas Micro Flows, Skiathos, Greece, 6 - 8 June 2012. Published in: Journal of Physics : Conference Series, Volume 362 Article number 012044. doi:10.1088/1742-6596/362/1/012044 ISSN 1742-6596.

Research output not available from this repository.

Request-a-Copy directly from author or use local Library Get it For Me service.

Request Changes to record.

Abstract

In this paper we describe a numerical method for the efficient time-accurate coupling of hybrid continuum/molecular micro gas flow solvers. Hybrid approaches are commonly used when non-equilibrium effects in the flow field are spatially localized; in these regions a more accurate, but typically more expensive, solution procedure is adopted. Although this can greatly increase efficiency in steady flows, in unsteady flows the evolution of the solution as a whole is restricted by the maximum time step allowed by the molecular-based/kinetic model; numerically speaking, this is a stiff problem. In the method presented in this paper we exploit time-scale separation, when it exists, to partially decouple the temporal evolution of the two parts of the hybrid model. This affords major computational savings. The method is a modified/extended version of the seamless heterogeneous multiscale method (SHMM). Our approach allows multiple micro steps (molecular steps) before coupling with the macro (continuum) solver: we call this a multi-step SHMM. This maintains the main advantages of SHMM (computational speed-up and flexible application) while improving on accuracy and greatly reducing the number of continuum computations and instances of coupling required. The improved accuracy of the multi-step SHMM is demonstrated for two canonical one-dimensional transient flows (oscillatory Poiseuille and oscillatory Couette flow) and for rarefied-gas oscillatory Poiseuille flow.

Item Type:	Conference Item (Paper)
Divisions:	Faculty of Science, Engineering and Medicine > Engineering > Engineering
Journal or Publication Title:	Journal of Physics : Conference Series
Publisher:	Institute of Physics Publishing Ltd.
ISSN:	1742-6596
Official Date:	2012
Dates:	Date Event 2012 UNSPECIFIED
Volume:	Volume 362
Page Range:	Article number 012044
DOI:	10.1088/1742-6596/362/1/012044
Status:	Peer Reviewed
Publication Status:	Published
Conference Paper Type:	Paper
Title of Event:	1st European Conference on Gas Micro Flows
Type of Event:	Conference
Location of Event:	Skiathos, Greece
Date(s) of Event:	6 - 8 June 2012

Request changes or add full text files to a record

Repository staff actions (login required)

View Item