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Monte Carlo Solution of Boltzmann Equation for a Simple Model of Highly Nonequilibrium Diatomic Gases : Translational Rotational Energy Relaxation
https://jaxa.repo.nii.ac.jp/records/34538
https://jaxa.repo.nii.ac.jp/records/345380970bfbe-19ac-41ea-abea-b8bb461df099
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
SA2401305.pdf (1.6 MB)
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| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||||
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| 公開日 | 2015-03-26 | |||||||
| タイトル | ||||||||
| タイトル | Monte Carlo Solution of Boltzmann Equation for a Simple Model of Highly Nonequilibrium Diatomic Gases : Translational Rotational Energy Relaxation | |||||||
| 言語 | en | |||||||
| 言語 | ||||||||
| 言語 | eng | |||||||
| 資源タイプ | ||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||||
| 資源タイプ | departmental bulletin paper | |||||||
| 著者 |
YOSHIKAWA, Kenneth K.
× YOSHIKAWA, Kenneth K.
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| 著者所属（英） | ||||||||
| en | ||||||||
| (Present address)Ames Research Center,NASA,Moffett Field | ||||||||
| 出版者 | ||||||||
| 出版者 | 東京大学宇宙航空研究所 | |||||||
| 出版者（英） | ||||||||
| 出版者 | Institute of Space and Aeronautical Science,University of Tokyo | |||||||
| 書誌情報 |
en : ISAS report/Institute of Space and Aeronautical Science,University of Tokyo 巻 43, 号 6, p. 73-110, 発行日 1978-06 |
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| 抄録（英） | ||||||||
| 内容記述タイプ | Other | |||||||
| 内容記述 | Theoretical studies of translational and rotational energy relaxation in diatomic gases are described. The direct simulation Monte Carlo method is employed to solve the Boltzmann equation for a rotationally excited highly nonequilibrium gas. The gas investigated is homonuclear diatomic nitrogen, and the semiclassical model of Itikawa is incorporated for the transition probability that describes rotation-translation energy interchange. The details of energy interchange between the translational motion and the rotational energy levels of the gas are examined for spatially uniform flow without boundary interactions (the "box" calculation) with a variety of initial conditions. The results show : 1. The assumption that relaxation occurs via successive local Maxwellian velocity distributions, which is a commonly used basis for finding approximate solutions of Boltzmann equation, is not valid for gases that are initially in highly nonequilibrium states. This is especially true for initial conditions that involve low translational and high rotational temperatures. 2. The energy distributions for such transitions show bimodal (or double peak) relaxation patterns; the secondary peak ("satellite peak") appears around the Maxwellian elastic peak in the velocity distribution early during the relaxation period. The secondary peak is due to inelastic collisions and is analogous to the rotational Raman effect accompanying Rayleigh scattering. 3. The rotational energy distribution also shows bimodal relaxation effects : In addtion to thermal equilibrium Boltzmann peak, a weak peak also appears at the high rotational energy levels. When the rotational energy distribution is a delta function, however, relaxation proceeds only as a single-peak distribution. One, therefore, concludes that single- or double-peak relaxation depends on the type of initial distributions assumed. 4. Relaxation of the velocity distribution to equilibrium Maxwellian occurs relatively fast while the rotational energy relaxes more slowly. The relaxation time depends not only on equilibrium temperature, but also on initial velocity and rotational energy distributions. Close correlation of the relaxation between the box models and fluid flows, such as, sound absorption, shock wave, and free-jet expansion experiment are described. Also presented are brief preliminary results of a shock wave showing translational and rotational energy relaxation structure. A 16-mm movie film displays examples of the relaxation effects of the "box" model with a variety of initially specified velocity and rotational energy distributions. | |||||||
| ISSN | ||||||||
| 収録物識別子タイプ | ISSN | |||||||
| 収録物識別子 | 0372-1418 | |||||||
| 書誌レコードID | ||||||||
| 収録物識別子タイプ | NCID | |||||||
| 収録物識別子 | AA00675986 | |||||||
| 資料番号 | ||||||||
| 内容記述タイプ | Other | |||||||
| 内容記述 | 資料番号: SA2401305000 | |||||||
