Detailed simulation of morphodynamics: 1. Hydrodynamic model

Nabi M.; de Vriend H. J.; Mosselman E.; Sloff C. J.; Shimizu Y.

Title	en Detailed simulation of morphodynamics: 1. Hydrodynamic model
Creator	en Nabi, M. en de Vriend, H. J. en Mosselman, E. en Sloff, C. J. en Shimizu, Y. NRID 1000020261331
Accessrights	open access
Rights	en ©2012 American Geophysical Union
Subject	Other en Cartesian grid Other en dunes Other en large eddy simulation Other en multigrid Other en ripples Other en river morphodynamics NDC 517
Description	Abstract en We present a three-dimensional high-resolution hydrodynamic model for unsteady incompressible flow over an evolving bed topography. This is achieved by using a multilevel Cartesian grid technique that allows the grid to be refined in high-gradient regions and in the vicinity of the river bed. The grid can be locally refined and adapted to the bed geometry, managing the Cartesian grid cells and faces using a hierarchical tree data approach. A ghost-cell immersed-boundary technique is applied to cells intersecting the bed topography. The governing equations have been discretized using a finite-volume method on a staggered grid, conserving second-order accuracy in time and space. The solution advances in time using the fractional step approach. Large-eddy simulation is used as turbulence closure. We validate the model against several experiments and other results from literature. Model results for Stokes flow around a cylinder in the vicinity of a moving wall agree well with Wannier's analytical solution. At higher Reynolds numbers, computed trailing bubble length, separation angle, and drag coefficient compare favorably with experimental and previous computational results. Results for the flow over two- and three-dimensional dunes agree well with published data, including a fair reproduction of recirculation zones, horse-shoe structures, and boiling effects. This shows that the model is suitable for being used as a hydrodynamic submodel in the high-resolution modeling of sediment transport and formation and evolution of subaqueous ripples and dunes.
Publisher	en American Geophysical Union
Date	Issued2012-12-20
Language	eng
Resource Type	journal article
Version Type	VoR
Identifier	HDL http://hdl.handle.net/2115/52931
Relation	isIdenticalTo DOI https://doi.org/10.1029/2012WR011911
Journal	PISSN 0043-1397 en Water Resources Research Volume Number48 Issue Number12 Page StartW12523
File	fulltext WRR48-12_W12523.pdf 3.08 MB (application/pdf) Issued2012-12-20
Oaidate	2023-07-26