Publikationsdatum:
2022-05-26
Beschreibung:
Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Advances in Water Resources 111 (2018): 435-451, doi:10.1016/j.advwatres.2017.11.019.
Beschreibung:
A Reynolds-averaged Euler–Lagrange sediment transport model (CFDEM-EIM) was developed for steady sheet flow, where the inter-granular interactions were resolved and the flow turbulence was modeled with a low Reynolds number corrected turbulence closure modified for two-phase flows. To model the effect of turbulence on the sediment suspension, the interaction between the turbulent eddies and particles was simulated with an eddy interaction model (EIM). The EIM was first calibrated with measurements from dilute suspension experiments. We demonstrated that the eddy-interaction model was able to reproduce the well-known Rouse profile for suspended sediment concentration. The model results were found to be sensitive to the choice of the coefficient, C0, associated with the turbulence-sediment interaction time. A value was suggested to match the measured concentration in the dilute suspension. The calibrated CFDEM-EIM was used to model a steady sheet flow experiment of lightweight coarse particles and yielded reasonable agreements with measured velocity, concentration and turbulence kinetic energy profiles. Further numerical experiments for sheet flow suggested that when C0 was decreased to C0 〈 3, the simulation under-predicted the amount of suspended sediment in the dilute region and the Schmidt number is over-predicted (Sc 〉 1.0). Additional simulations for a range of Shields parameters between 0.3 and 1.2 confirmed that CFDEM-EIM was capable of predicting sediment transport rates similar to empirical formulations. Based on the analysis of sediment transport rate and transport layer thickness, the EIM and the resulting suspended load were shown to be important when the fall parameter is less than 1.25.
Beschreibung:
Z. Cheng and T.-J. Hsu were supported by the U.S. Office of Naval Research (N00014-
16-1-2853) and National Science Foundation (OCE- 1537231). J. Chauchat was supported
by the Région Rhones-Alpes (COOPERA project and Explora Pro grant) and the French
national programme EC2CO-LEFE MODSED. J. Calantoni was supported under base
funding to the U.S. Naval Research Laboratory from the U.S. Office of Naval Research.
The authors would also like to acknowledge the support from the program on "Fluid-
Mediated Particle Transport in Geophysical Flows" at the Kavli Institute for Theoretical
Physics, Santa Barbara, USA.
Schlagwort(e):
Euler-Lagrange model
;
Eddy interaction model
;
Turbulent suspension
;
Steady sheet flow
;
Rouse profile
;
Sediment transport rate
Repository-Name:
Woods Hole Open Access Server
Materialart:
Preprint
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