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On the surface expression of bottom features in free-surface flow

Published online by Cambridge University Press:  13 August 2020

Saksham Gakhar Open the ORCID record for Saksham Gakhar [Opens in a new window] ,
Jeffrey R. Koseff Open the ORCID record for Jeffrey R. Koseff [Opens in a new window]  and
Nicholas T. Ouellette Open the ORCID record for Nicholas T. Ouellette [Opens in a new window]
Saksham Gakhar*
Affiliation:
Department of Civil and Environmental Engineering, The Bob and Norma Street Environmental Fluid Mechanics Laboratory, Stanford University, Stanford, CA94305, USA
Jeffrey R. Koseff
Affiliation:
Department of Civil and Environmental Engineering, The Bob and Norma Street Environmental Fluid Mechanics Laboratory, Stanford University, Stanford, CA94305, USA
Nicholas T. Ouellette
Affiliation:
Department of Civil and Environmental Engineering, The Bob and Norma Street Environmental Fluid Mechanics Laboratory, Stanford University, Stanford, CA94305, USA
*
†Email address for correspondence: sakshamg@stanford.edu
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Abstract

Laboratory experiments were carried out in an open-channel recirculating water flume for different bottom treatments and a variety of flow conditions. We acquired overhead images of the free surface downstream of the bottom features and used these to train convolutional neural network based classifiers. Using these classifiers, we demonstrate that information acquired at the surface alone can be used to differentiate between the physical features that lie at the bottom boundary. We show that although external physical processes, such as winds, can modulate the free surface, they do not necessarily eliminate the free-surface signature of the submerged bottom features. Our results provide strong motivation for future studies that probe the physical processes responsible for transporting information about the bottom of the flow to the surface.

JFM classification

Geophysical and Geological Flows: Topographic effects Waves/Free-surface Flows: Channel flow Geophysical and Geological Flows: Shallow water flows
Type
JFM Papers
Information
Journal of Fluid Mechanics , Volume 900 , 10 October 2020 , A41
Copyright
© The Author(s), 2020. Published by Cambridge University Press

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References

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