| 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.
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| Source Publication | Acta Mechanica Sinica
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| 2014-04 | |
| Volume | 30Issue:2Pages:133-143 |
| ISSN | 0567-7718 |
| Abstract | 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. |
| Keyword | Bgk Model Boltzmann Equation Validity Evaluation Dsmc Method Time Relaxation |
| URL | 查看原文 |
| Indexed By | SCI ; EI ; CSCD |
| Language | 英语 |
| WOS ID | WOS:000334677600002 |
| Funding Organization | The project was supported by the National Natural Science Foundation of China (91116013, 11372325, and 11111120080). |
| Department | LHD微尺度和非平衡流动 |
| Classification | 二类 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://dspace.imech.ac.cn/handle/311007/48847 |
| Collection | 高温气体动力学国家重点实验室 |
| Corresponding Author | Sun, QH (reprint author), Chinese Acad Sci, Inst Mech, State Key Lab High Temp Gas Dynam, Beijing 100190, Peoples R China. |
| Recommended Citation 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. |
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