Goldsmith, KJA orcid.org/0000-0002-7679-3348 and Pittard, JM orcid.org/0000-0003-2244-5070 (2018) A comparison of shock-cloud and wind-cloud interactions: effect of increased cloud density contrast on cloud evolution. Monthly Notices of the Royal Astronomical Society, 476 (2). pp. 2209-2219. ISSN 0035-8711
Abstract
The similarities, or otherwise, of a shock or wind interacting with a cloud of density contrast χ = 10 were explored in a previous paper. Here, we investigate such interactions with clouds of higher density contrast. We compare the adiabatic hydrodynamic interaction of a Mach 10 shock with a spherical cloud of χ = 10^3 with that of a cloud embedded in a wind with identical parameters to the post-shock flow. We find that initially there are only minor morphological differences between the shock–cloud and wind–cloud interactions, compared to when χ = 10. However, once the transmitted shock exits the cloud, the development of a turbulent wake and fragmentation of the cloud differs between the two simulations. On increasing the wind Mach number, we note the development of a thin, smooth tail of cloud material, which is then disrupted by the fragmentation of the cloud core and subsequent ‘mass-loading’ of the flow. We find that the normalized cloud mixing time (tmix) is shorter at higher χ. However, a strong Mach number dependence on tmix and the normalized cloud drag time, tdrag, is not observed. Mach-number-dependent values of tmix and tdrag from comparable shock–cloud interactions converge towards the Mach-number-independent time-scales of the wind–cloud simulations. We find that high χ clouds can be accelerated up to 80–90 per cent of the wind velocity and travel large distances before being significantly mixed. However, complete mixing is not achieved in our simulations and at late times the flow remains perturbed.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. Available online in it's definitive format; https://doi.org/10.1093/mnras/sty401 |
Keywords: | hydrodynamics, shock waves, stars: winds, outflows, ISM: clouds, ISM: kinematics and dynamics |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Funding Information: | Funder Grant number Science & Technology Facilities Council (STFC) ST/P00041X/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 16 May 2018 12:57 |
Last Modified: | 16 Dec 2024 14:15 |
Status: | Published |
Publisher: | Oxford University Press |
Identification Number: | 10.1093/mnras/sty401 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:130881 |