Large‐eddy simulation of the tidal‐cycle variations of an estuarine boundary layer

Li, Ming; Radhakrishnan, Senthil K.; Piomelli, Ugo; Geyer, W. Rockwell

doi:10.1029/2009jc005702

Cited by 20 publications

(25 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Further up near the surface local shear production is smaller than local destruction of TKE and the deficit is supplied by the upward turbulent vertical diffusion of TKE from the boundary layer. This synoptic description and especially the importance of the vertical turbulent diffusion has been supported and complemented by observations from Shaw et al (2001) and Stacey (2003) and numerical simulations from Li et al (2010). A few studies have also explored the temporal variability of turbulent mixing.…”

Section: Introductionmentioning

confidence: 93%

Turbulence Dynamics at the Shoal–Channel Interface in a Partially Stratified Estuary

Collignon

Stacey

2013

Journal of Physical Oceanography

View full text Add to dashboard Cite

Turbulence observations at the shoal-channel interface in South San Francisco Bay are described and analyzed in this work. Profiles of turbulent kinetic energy (TKE) shear production and dissipation rate are estimated from ADCP beam velocities over a nine-day period during winter 2009 when the estuary was partially stratified. The TKE shear production profiles are consistent with a tidally driven bottom boundary layer, except late in the ebb when shear production intensifies and the region of maximum production is located in the upper half of the water column. A simple scaling for the depth-averaged TKE shear production based on bed friction performs well except during this late ebb period when it fails to predict the peak in shear production, which suggests that a mechanism other than bottom drag drives turbulence dynamics during this period. The profiles of TKE dissipation rates also display a late ebb peak. A lateral circulation develops at the shoal-channel interface during this late ebb period, and its effects on turbulence dynamics are investigated. An analytical framework is developed to identify and quantify these effects. Four mechanisms through which the lateral circulation can impact stability are identified, and two are found to be important during the late ebb period in South San Francisco Bay: the straining of the lateral density and velocity gradients in the lateral circulation. These results suggest that the lateral circulation acts to reduce the gradient Richardson number and is driving the late ebb peak in turbulence production and dissipation.

show abstract

Section: Introductionmentioning

confidence: 93%

Turbulence Dynamics at the Shoal–Channel Interface in a Partially Stratified Estuary

Collignon

Stacey

2013

Journal of Physical Oceanography

View full text Add to dashboard Cite

show abstract

“…We did a test model run that included the tidal forcing via the prescription of an oscillating body force [e.g., Li et al . ] and found the same result.…”

Section: Model Configurationmentioning

confidence: 99%

Roles of breaking waves and Langmuir circulation in the surface boundary layer of a coastal ocean

Gerbi

et al. 2013

J. Geophys. Res. Oceans

Self Cite

View full text Add to dashboard Cite

[1] Breaking waves and Langmuir circulation are two important turbulent processes in the wind-driven upper ocean. To investigate their roles in generating turbulence in the surface boundary layer of a coastal ocean, a large eddy simulation model is used to simulate the turbulence measurements collected at the Martha's Vineyard Coastal Observatory's Air-Sea Interaction Tower, during the Coupled Boundary Layers and Air-Sea Transfer (CBLAST) experiment in 2003. The model provides reasonable predictions for the vertical profiles of vertical velocity variance, turbulent kinetic energy (TKE), energy dissipation rates, and heat flux. It shows breaking waves dominating turbulence generation near the ocean surface and turbulent large eddies characteristic of Langmuir circulation deeper in the water column. Diagnostic analysis of TKE budget in the model shows a dominant balance between turbulent transport and dissipation near the surface and a dominant balance between shear production and dissipation at deeper depths. Although the Stokes production is a significant term in the TKE budget balance near the surface, it is smaller than shear production. The turbulent transport is large in the near-surface zone and is still significant in the region affected by Langmuir circulation. These results are in agreement with a conclusion inferred from a recent analysis of the near-surface turbulence measurements at the CBLAST site.

show abstract

“…Li et al [14] examined the inflow by performing LES to simulate the tidal-cycle variation of tidal flow, without the influence of turbines. Their work includes the effects of salinity and temperature stratification and a cyclically varying force that drives the flow.…”

mentioning

confidence: 99%

A large-eddy simulation study of wake propagation and power production in an array of tidal-current turbines

Churchfield

Moriarty

2013

Phil. Trans. R. Soc. A.

130

117

View full text Add to dashboard Cite

This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally periodic precursor simulation is performed to create turbulent flow data. Then those data are used as inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modelled using rotating actuator lines, and the finite-volume method is used to solve the governing equations. In studying the wakes created by the turbines, we observed that the vertical shear of the inflow combined with wake rotation causes lateral wake asymmetry. Also, various turbine configurations are simulated, and the total power production relative to isolated turbines is examined. We found that staggering consecutive rows of turbines in the simulated configurations allows the greatest efficiency using the least downstream row spacing. Counter-rotating consecutive downstream turbines in a non-staggered array shows a small benefit. This work has identified areas for improvement. For example, using a larger precursor domain would better capture elongated turbulent structures, and including salinity and temperature equations would account for density stratification and its effect on turbulence. Additionally, the wall shear stress modelling could be improved, and more array configurations could be examined.

show abstract

Large‐eddy simulation of the tidal‐cycle variations of an estuarine boundary layer

Cited by 20 publications

References 59 publications

Turbulence Dynamics at the Shoal–Channel Interface in a Partially Stratified Estuary

Turbulence Dynamics at the Shoal–Channel Interface in a Partially Stratified Estuary

Roles of breaking waves and Langmuir circulation in the surface boundary layer of a coastal ocean

A large-eddy simulation study of wake propagation and power production in an array of tidal-current turbines

Contact Info

Product

Resources

About