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Detailed simulation of morphodynamics: 1. Hydrodynamic model
| Title: | Detailed simulation of morphodynamics: 1. Hydrodynamic model |
| Authors: | Nabi, M. Browse this author | | de Vriend, H. J. Browse this author | | Mosselman, E. Browse this author | | Sloff, C. J. Browse this author | | Shimizu, Y. Browse this author →KAKEN DB |
| Keywords: | Cartesian grid | | dunes | | large eddy simulation | | multigrid | | ripples | | river morphodynamics |
| Issue Date: | 20-Dec-2012 |
| Publisher: | American Geophysical Union |
| Journal Title: | Water Resources Research |
| Volume: | 48 |
| Issue: | 12 |
| Start Page: | W12523 |
| Publisher DOI: | 10.1029/2012WR011911 |
| Abstract: | 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. |
| Rights: | ©2012 American Geophysical Union |
| Type: | article |
| URI: | http://hdl.handle.net/2115/52931 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 清水 康行
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