@Article{CiCP-28-1502,
author = {Chen , JianfengLiu , ShaWang , Yong and Zhong , Chengwen},
title = {A Compressible Conserved Discrete Unified Gas-Kinetic Scheme with Unstructured Discrete Velocity Space for Multi-Scale Jet Flow Expanding into Vacuum Environment},
journal = {Communications in Computational Physics},
year = {2020},
volume = {28},
number = {4},
pages = {1502--1535},
abstract = {<p style="text-align: justify;">The mechanism of jet flow expanding into vacuum environment (or extremely low density environment) is important for the propulsion unit of micro-electro-mechanical systems (MEMS), the thruster of spacecraft, the attitude control system of
satellite, etc.. Since its flow field is often composed of local continuum region and local rarefied region, the jet flow into vacuum has noteworthy multi-scale transportation
behaviors. Therefore, the numerical study of such flows needs the multi-scale schemes
which are valid for both continuum and rarefied flows. In the past few years, a series
of unified methods for whole flow regime (from continuum regime to rarefied regime)
have been developed from the perspective of the direct modeling, and have been verified by sufficient test cases. In this paper, the compressible conserved discrete unified
gas-kinetic scheme is further developed and is utilized for predicting the jet flows into
vacuum environment. In order to cover the working conditions of both aerospace and
MEMS applications, the jet flows with a wide range of inlet Knudsen (Kn) numbers
(from 1E-4 to 100) are considered. The evolution of flow field during the entire startup
and shutdown process with Kn number 100 is predicted by the present method, and
it matches well with the result of analytical collisionless Boltzmann equation. For Kn
numbers from 1E-4 to 10, the flow field properties such as density, momentum, and
pressure are investigated, and the results are provided in details, since the published
results are not sufficient at the present stage. The extent and intensity of the jet flow
influence are especially investigated, because they are strongly related to the plume
contamination and momentum impact on objects facing the jet, such as the solar paddles which face the attitude control thruster during the docking process.</p>},
issn = {1991-7120},
doi = {https://doi.org/10.4208/cicp.OA-2020-0037},
url = {http://global-sci.org/intro/article_detail/cicp/18109.html}
}