| 翻訳と辞書 |
| free molecular flow ： ウィキペディア英語版 |
free molecular flow
Free molecular flow describes the fluid dynamics of gas where the mean free path of the molecules is larger than the size of the chamber or of the object under test. For tubes/objects of the size of several cm, this means pressures well below 10−3 Torr. This is also called the regime of high vacuum. This is opposed to viscous flow encountered at higher pressures.〔Yamamoto, K.; Pack, D. C.; Transient free molecular flow through a tube; Rarefied gas dynamics; Proceedings of the Eleventh International Symposium, Cannes, France, July 3-8, 1978. Volume 1. (A80-34876 14-77) Paris, Commissariat a l'Energie Atomique, 1979, p. 207-218.〕
In free molecular flow, the pressure of the remaining gas can be considered as effectively zero. Thus, boiling points do not depend on the residual pressure. The flow can be considered to be individual particles moving in straight lines. Practically, the "vapor" cannot move around bends or into other spaces behind obstacles, as they simply hit the tube wall.
The definition of a free molecular flow depends on the distance scale under consideration. For example, in the interplanetary medium, the plasma is in a free molecular flow regime in scales less than 1 AU; thus, planets and moons are effectively under particle bombardment. However, on larger scales, fluid-like behavior is observed, because the probability of collisions between particles becomes significant.
==See also==
* Knudsen equation
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「free molecular flow」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|