Ambient Entrainment Mechanisms of Partially Unconfined Turbidity Currents Interacting with a Continuous Rigid Obstacle
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 147, Issue 3
Abstract
In this study, the entrainment mechanisms of unconfined turbidity currents that interact with a linear rectangular obstacle will be investigated and compared with confined studies. Laboratory experiments will be performed in a lock exchange basin, where the width allows unconfined and partially unconfined flows, with varying initial current densities. Ambient fluid entrainment, based on the Morton-Taylor-Turner (MTT) hypothesis, was found to be comparable to previous confined studies; however, in situ current density decreased at a greater rate than the latter. It was shown that this was probably caused by the unconfined lateral spreading of the current before the obstacle. The entrainment parameter had a weak relationship with Froude, Reynolds, and Richardson numbers for nonobstructed tests, which was similar to previous studies. However, this was not the case for obstacle tests, which experienced a greater variance in entrainment velocity and head height. Of note, head height was less than that for equivalent confined tests, which suggested that in a practical setting, confined studies might overestimate the obstacle height needed to block current propagation.
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Acknowledgments
We would like to thank Trevor Patrick, Geoff Kirby, and Jim Luo for their help in constructing and installing the required experimental components.
Data Availability Statement
The data that supports the findings of this study are available from the corresponding author upon reasonable request.
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Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 147 • Issue 3 • May 2021
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© 2021 American Society of Civil Engineers.
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Received: Aug 16, 2020
Accepted: Nov 6, 2020
Published online: Jan 29, 2021
Published in print: May 1, 2021
Discussion open until: Jun 29, 2021
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