Eulerian two-phase modeling of wave orbital ripples: a sensitivity study on closure models
| Author(s) | Zhang, Jiaye | |
| Date Accessioned | 2021-11-18T12:51:27Z | |
| Date Available | 2021-11-18T12:51:27Z | |
| Publication Date | 2021 | |
| SWORD Update | 2021-08-11T16:05:39Z | |
| Abstract | A two-dimensional simulation of sediment transport over wave orbital ripples driven by onshore velocity-skewed oscillatory flow using a Eulerian two-phase flow model, SedFoam, is presented to investigate the sensitivity of the turbulence closure models with respect to sediment transport and ripple migration. The comparison of simulation results between k-ɛ model and k-ω SST model at equilibrium stage confirms that the k-ω SST model predicts a significantly weaker vortices evolution in orbital ripple field, which causes less suspended sediment transport during a wave period. The resulting equilibrium ripple steepness is also under-predicted. An in-depth analysis reveals that the negative component of cross-diffusion term neglected in k-ω SST model results in weaker turbulence and lower turbulent suspension. Hence, a larger onshore near-bed sediment transport and a smaller offshore suspended load transport are obtained. Consequently, the model with k-ω SST closure over-predicts the onshore ripple migration rate. The root cause of which the neglected negative cross-diffusion term leads to the under-prediction of primary vortices on the ripple flanks under oscillatory flows is worth of further investigation. | en_US |
| Advisor | Hsu, Tian-Jian | |
| Degree | M.C.E. | |
| Department | University of Delaware, Department of Civil and Environmental Engineering | |
| Unique Identifier | 1285538423 | |
| URL | https://udspace.udel.edu/handle/19716/29419 | |
| Language | en | |
| Publisher | University of Delaware | en_US |
| URI | https://login.udel.idm.oclc.org/login?url=https://www.proquest.com/dissertations-theses/eulerian-two-phase-modeling-wave-orbital-ripples/docview/2572570797/se-2?accountid=10457 | |
| Keywords | Ripple migration | |
| Keywords | Sediment transport | |
| Keywords | Turbulence closure models | |
| Keywords | Two-phase modeling | |
| Keywords | Wave orbital ripples | |
| Title | Eulerian two-phase modeling of wave orbital ripples: a sensitivity study on closure models | en_US |
| Type | Thesis | en_US |