Volume 9, 2017Progress in Flight Physics
|Page(s)||349 - 362|
|Section||Nonequilibrium and rarefied flows|
|Published online||20 June 2017|
Parametric study on propulsion performance of microtubes
Laboratory of Transport Phenomena Department of Mechanical Engineering, University of Thessaly Pedion Areos, Volos 38334, Greece
The pressure-driven rarefied gas §ow of polyatomic gases through short tubes in a wide range of the Knudsen number is numerically investigated. The downstream over the upstream pressure ratio is taken very close to zero. Such flows are characterized by low Reynolds numbers and high viscous losses and, therefore, short circular microtubes may be used instead of typical micronozzles. The main computed quantities include the flow rate, the discharge coefficient, the thrust, and the impulse factor which are provided in terms of the gas rarefaction and the tube dimensionless length. Based on the above, a parametric study on the propulsion characteristics of microtubes is provided. Furthermore, a comparison between corresponding polyatomic and monoatomic results is performed and the effect of the internal degrees of freedom on the results is investigated.
© The Authors, published by EDP Sciences, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.