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Fluid density effects in supersonic jet-induced cratering in a granular bed on a planetary body having an atmosphere in the continuum regime

Balakrishnan, Kaushik and Bellan, Josette (2021) Fluid density effects in supersonic jet-induced cratering in a granular bed on a planetary body having an atmosphere in the continuum regime. Journal of Fluid Mechanics, 915 . Art. No. A29. ISSN 0022-1120. doi:10.1017/jfm.2021.29. https://resolver.caltech.edu/CaltechAUTHORS:20210414-125248593

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Abstract

To investigate the effect of atmospheric density and jet-fluid density during supersonic jet-induced cratering on a granular particle bed, large eddy simulation (LES) for the fluid phase coupled with a granular flow model based on kinetic theory is used. Coupling accounts for momentum and energy interaction between particles and fluid. Several simulations are conducted that enable discriminating between the crater characteristics which depend on the atmospheric (or jet) density, and those which depend on the ratio between jet-fluid density and atmospheric density. The crater cross-sectional shapes are controlled by the density ratio between jet fluid and atmosphere. For large such ratios, the craters have a parabolic cross-section shape, are relatively shallow, have large diameters and have subdued ejecta. In contrast, for ratios close to unity, the craters have a conical cross-section, are relatively deep, have relatively small diameters and have substantial ejecta; these craters also display ripples on their walls. The physics leading to these differences is explained. Considerations of particle momentum flux indicate that at same fraction of the crater depth and same radial distance from the jet axis, the radial and vertical components have larger magnitudes for conical craters than for parabolic craters. The spatial distribution of the ratio between the drag force and the force due to the particles resistance to compaction are compared and it is found to be dependent on the jet-to-atmospheric fluid density ratio. A few features of the crater, in particular its depth, only depend on the atmospheric (or jet) fluid density.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1017/jfm.2021.29DOIArticle
ORCID:
AuthorORCID
Bellan, Josette0000-0001-9218-7017
Additional Information:© The Author(s), 2021. Published by Cambridge University Press. Received 29 April 2020; revised 11 November 2020; accepted 30 December 2020. The computational time was provided by the NASA Science Mission Directorate and the computations were performed on the NASA Ames Supercomputer system. Professor W.S. Don (Brown University) provided the parallelization framework. Dr G. Jost (NASA Ames) helped in timing studies to improve simulation performance. This study was conducted at the Jet Propulsion Laboratory (JPL) of the California Institute of Technology (Caltech) and was sponsored by the Lunar LASER program and by the Particle-Surface Interaction, Grand Challenge program from the National Aeronautics and Space Administration (NASA). The authors report no conflict of interest.
Funders:
Funding AgencyGrant Number
NASA/JPL/CaltechUNSPECIFIED
Subject Keywords:high-speed flow, granular media
DOI:10.1017/jfm.2021.29
Record Number:CaltechAUTHORS:20210414-125248593
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20210414-125248593
Official Citation:Balakrishnan, K., & Bellan, J. (2021). Fluid density effects in supersonic jet-induced cratering in a granular bed on a planetary body having an atmosphere in the continuum regime. Journal of Fluid Mechanics, 915, A29. doi:10.1017/jfm.2021.29
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:108728
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:14 Apr 2021 22:04
Last Modified:19 Apr 2021 16:59

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