On the validity of the Boltzmann-BGK model through relaxation evaluation

	On the validity of the Boltzmann-BGK model through relaxation evaluation
	Sun QH(孙泉华); Cai CP; Gao W(高巍); Sun, QH (reprint author), Chinese Acad Sci, Inst Mech, State Key Lab High Temp Gas Dynam, Beijing 100190, Peoples R China.
发表期刊	Acta Mechanica Sinica
	2014-04
卷号	30 期号:2 页码:133-143
ISSN	0567-7718
摘要	The Boltzmann-Bhatnagar-Gross-Krook (BGK) model is investigated for its validity regarding the collision term approximation through relaxation evaluation. The evaluation is based on theoretical analysis and numerical comparison between the BGK and direct simulation Monte Carlo (DSMC) results for three specifically designed relaxation problems. In these problems, one or half component of the velocity distribution is characterized by another Maxwellian distribution with a different temperature. It is analyzed that the relaxation time in the BGK model is unequal to the molecular mean collision time. Relaxation of component distribution fails to involve enough contribution from other component distributions, which makes the BGK model unable to capture details of velocity distribution, especially when discontinuity exists in distribution. The BGK model, however, predicts satisfactory results including fluxes during relaxation when the temperature difference is small. Particularly, the model-induced error in the BGK model increases with the temperature difference, thus the model is more reliable for low-speed rarefied flows than for hypersonic flows.
关键词	Bgk Model Boltzmann Equation Validity Evaluation Dsmc Method Time Relaxation
URL	查看原文
收录类别	SCI ; EI ; CSCD
语种	英语
WOS记录号	WOS:000334677600002
项目资助者	The project was supported by the National Natural Science Foundation of China (91116013, 11372325, and 11111120080).
课题组名称	LHD微尺度和非平衡流动
论文分区	二类
引用统计	被引频次：5[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://dspace.imech.ac.cn/handle/311007/48847
专题	高温气体动力学国家重点实验室
通讯作者	Sun, QH (reprint author), Chinese Acad Sci, Inst Mech, State Key Lab High Temp Gas Dynam, Beijing 100190, Peoples R China.
推荐引用方式 GB/T 7714	Sun QH,Cai CP,Gao W,et al. On the validity of the Boltzmann-BGK model through relaxation evaluation[J]. Acta Mechanica Sinica,2014,30,2,:133-143.
APA	Sun QH,Cai CP,Gao W,&Sun, QH .(2014).On the validity of the Boltzmann-BGK model through relaxation evaluation.Acta Mechanica Sinica,30(2),133-143.
MLA	Sun QH,et al."On the validity of the Boltzmann-BGK model through relaxation evaluation".Acta Mechanica Sinica 30.2(2014):133-143.

条目包含的文件		下载所有文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
IMCAS-J2014-120.pdf（860KB）			开放获取	--	浏览下载