On the role of transverse motion in pseudo-steady gravity currents

Marshall, C. R.; Dorrell, R. M.; Keevil, G. M.; Peakall, J.; Tobias, S. M.

Abstract

Flow in the body of gravity currents is typically assumed to be statistically two-dimensional, and cross-stream flow is often neglected (Simpson 1997; Meiburg et al. 2015). Here, we assess the validity of such assumptions using Shake-the-Box particle tracking velocimetry measurements of experimental gravity current flows. The resulting instantaneous, volumetric, whole-field velocity measurements indicate that cross-stream and vertical velocities (and velocity fluctuations) are equivalent in magnitude and thus are key to energy distribution and dissipation within the flow. Further, the presented data highlight the limitations of basing conclusions regarding body structure on a single cross-stream plane (particularly if that plane is central). Spectral analysis and dynamic mode decomposition of the fully three-dimensional, volumetric velocity data suggests internal waves within the current body that are associated with coherent three-dimensional motions in higher Reynolds number flows. Additionally, a potential critical layer at the height of the downstream velocity maximum is identified.

Citation

Marshall, C. R., Dorrell, R. M., Keevil, G. M., Peakall, J., & Tobias, S. M. (2023). On the role of transverse motion in pseudo-steady gravity currents. Experiments in Fluids, 64(3), Article 63. https://doi.org/10.1007/s00348-023-03599-7

• Journal Article Type: Article
• Acceptance Date: Jan 31, 2023
• Online Publication Date: Mar 11, 2023
• Publication Date: Mar 1, 2023
• Deposit Date: Feb 19, 2024
• Publicly Available Date: Feb 20, 2024
• Journal: Experiments in Fluids
• Print ISSN: 0723-4864
• Electronic ISSN: 1432-1114
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• Volume: 64
• Issue: 3
• Article Number: 63
• DOI: https://doi.org/10.1007/s00348-023-03599-7
• Public URL: https://hull-repository.worktribe.com/output/4249354