Numerical investigation of rarefied vortex loop formation due to shock wave diffraction with the use of rorticity

Cao, Z., White, C. and Kontis, K. (2021) Numerical investigation of rarefied vortex loop formation due to shock wave diffraction with the use of rorticity. Physics of Fluids, 33(6), 067112. (doi: 10.1063/5.0054289)

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When compressed gas is ejected from a nozzle into a low-pressure environment, the shock wave diffracts around the nozzle lip and a vortex loop will form. The phenomenon has been widely investigated in the continuum flow regime, but how the shock diffraction and vortex behave under rarefied flow conditions has not received as much attention. It is necessary to understand this transient flow in rarefied environments to improve thrust vector control and avoid potential contamination and erosion of spacecraft surfaces. This work provides numerical results of the vortex loop formation caused by shock wave diffraction around a 90° corner using the direct simulation Monte Carlo method and the compressible Navier–Stokes equations with the appropriate Maxwell velocity slip and the von Smoluchowski temperature jump boundary conditions. The Mach number and rarefaction effects on the formation and evolution of the vortex loop are discussed. A study of the transient structures of vortex loops has been performed using the rorticity concept. A relationship of mutual transformation between the rorticity and shear vectors has been discovered, demonstrating that the application of this concept is useful to understand vortex flow phenomena.

Item Type:Articles
Glasgow Author(s) Enlighten ID:CAO, Ziqu and White, Dr Craig and Kontis, Professor Konstantinos
Authors: Cao, Z., White, C., and Kontis, K.
College/School:College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
Journal Name:Physics of Fluids
Publisher:American Institute of Physics
ISSN (Online):1089-7666
Published Online:16 June 2021
Copyright Holders:Copyright © 2021 The Authors
First Published:First published in Physics of Fluids 33(6):067112
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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