Wave-Created Mud Suspensions: A Theoretical Study
We studied wave-created high-density mud suspensions (fluid mud) using a one-dimensional water column (1DV) model that includes k-ε turbulence closure at a high vertical resolution with a vertical grid spacing of 1 mm. The k-ε turbulence model includes two sediment-related dissipation terms associat...
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doaj-a0bf9cff891349f482614d376dd1959f2021-04-02T06:40:58ZengMDPI AGJournal of Marine Science and Engineering2077-13122018-03-01622910.3390/jmse6020029jmse6020029Wave-Created Mud Suspensions: A Theoretical StudyJochen Kämpf0Paul M. Myrow1College of Science & Engineering, Flinders University, PO Box 2100, Adelaide, SA 5001, AustraliaDepartment of Geology, The Colorado College, 14 E. Cache La Poudre, Colorado Springs, CO 80903, USAWe studied wave-created high-density mud suspensions (fluid mud) using a one-dimensional water column (1DV) model that includes k-ε turbulence closure at a high vertical resolution with a vertical grid spacing of 1 mm. The k-ε turbulence model includes two sediment-related dissipation terms associated with vertical density stratification and viscous drag of flows around sediment particles. To this end, the calibrated model reproduces the key characteristics (maximum concentration and thickness) of fluid mud layers created in laboratory experiments over a large range of wave velocities from 10 to 55 cm/s. The findings demonstrate that the equilibrium near-bed mud concentration, Cb, is solely determined from the balance between erosion and deposition fluxes, whereas the thickness of the fluid mud layer is mainly controlled by sediment-induced density stratification, which dissipates turbulence and hence eliminates turbulent sediment diffusivity at the top of the fluid mud layer, the lutocline. Our model stands in contrast to those that suggest that upward sediment diffusion is close to zero at the interface between the fluid mud layer and the overlying fluid. Instead, our model suggests that the upward diffusive flux of fluid mud flows peak at the lutocline and is compensated for enhanced settling fluxes just above it. Our model findings also support the existence of the gelling-ignition process, which is critical for the development of fluid mud beds in modern sedimentary environments.http://www.mdpi.com/2077-1312/6/2/29fluid mudsuspended sediment dynamicsgelling pointnumerical modellingtheory |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Jochen Kämpf Paul M. Myrow |
spellingShingle |
Jochen Kämpf Paul M. Myrow Wave-Created Mud Suspensions: A Theoretical Study Journal of Marine Science and Engineering fluid mud suspended sediment dynamics gelling point numerical modelling theory |
author_facet |
Jochen Kämpf Paul M. Myrow |
author_sort |
Jochen Kämpf |
title |
Wave-Created Mud Suspensions: A Theoretical Study |
title_short |
Wave-Created Mud Suspensions: A Theoretical Study |
title_full |
Wave-Created Mud Suspensions: A Theoretical Study |
title_fullStr |
Wave-Created Mud Suspensions: A Theoretical Study |
title_full_unstemmed |
Wave-Created Mud Suspensions: A Theoretical Study |
title_sort |
wave-created mud suspensions: a theoretical study |
publisher |
MDPI AG |
series |
Journal of Marine Science and Engineering |
issn |
2077-1312 |
publishDate |
2018-03-01 |
description |
We studied wave-created high-density mud suspensions (fluid mud) using a one-dimensional water column (1DV) model that includes k-ε turbulence closure at a high vertical resolution with a vertical grid spacing of 1 mm. The k-ε turbulence model includes two sediment-related dissipation terms associated with vertical density stratification and viscous drag of flows around sediment particles. To this end, the calibrated model reproduces the key characteristics (maximum concentration and thickness) of fluid mud layers created in laboratory experiments over a large range of wave velocities from 10 to 55 cm/s. The findings demonstrate that the equilibrium near-bed mud concentration, Cb, is solely determined from the balance between erosion and deposition fluxes, whereas the thickness of the fluid mud layer is mainly controlled by sediment-induced density stratification, which dissipates turbulence and hence eliminates turbulent sediment diffusivity at the top of the fluid mud layer, the lutocline. Our model stands in contrast to those that suggest that upward sediment diffusion is close to zero at the interface between the fluid mud layer and the overlying fluid. Instead, our model suggests that the upward diffusive flux of fluid mud flows peak at the lutocline and is compensated for enhanced settling fluxes just above it. Our model findings also support the existence of the gelling-ignition process, which is critical for the development of fluid mud beds in modern sedimentary environments. |
topic |
fluid mud suspended sediment dynamics gelling point numerical modelling theory |
url |
http://www.mdpi.com/2077-1312/6/2/29 |
work_keys_str_mv |
AT jochenkampf wavecreatedmudsuspensionsatheoreticalstudy AT paulmmyrow wavecreatedmudsuspensionsatheoreticalstudy |
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