Type
Conference PaperAuthors
Li, JunDate
2012-11-27Preprint Posting Date
2012-07-04Online Publication Date
2012-11-27Print Publication Date
2012Permanent link to this record
http://hdl.handle.net/10754/552544
Metadata
Show full item recordAbstract
Recently, the DSBGK method (Note: the original name DS-BGK is changed to DSBGK for simplicity) was proposed to reduce the stochastic noise in simulating rarefied gas flows at low velocity. Its total computational time is almost independent of the magnitude of deviation from equilibrium state. It was verified by the DSMC method in different benchmark problems over a wide range of Kn number. Some simulation results of the closed lid-driven cavity flow, thermal transpiration flow and the open channel flow by the DSBGK method are given here to show its efficiency and numerical stability. In closed problems, the density distribution is subject to unphysical fluctuation due to the absence of density constraint at the boundary. Thus, many simulated molecules are employed by DSBGK simulations to improve the stability and reduce the magnitude of fluctuation. This increases the memory usage remarkably but has small influence to the efficiency of DSBGK simulations. In open problems, the DSBGK simulation remains stable when using about 10 simulated molecules per cell because the fixed number densities at open boundaries eliminate the unphysical fluctuation. Small modification to the CLL reflection model is introduced to further improve the efficiency slightly.Citation
Efficiency and stability of the DSBGK method. AIP Conference Proceedings 1501 , 849 (2012); doi: 10.1063/1.4769631Publisher
AIP PublishingConference/Event name
28th International Symposium on Rarefied Gas Dynamics 2012, RGD 2012arXiv
1207.1040Additional Links
http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4769631http://arxiv.org/abs/1207.1040
ae974a485f413a2113503eed53cd6c53
10.1063/1.4769631