Sediment transport and morphodynamics generated by a dam-break swash uprush: Coupled vs uncoupled modeling

Postacchini, Matteo; Othman, Ilya Khairanis; Brocchini, Maurizio; Baldock, Tom E.

doi:10.1016/j.coastaleng.2014.04.003

Cited by 28 publications

(23 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To study an isolated swash event, laboratory studies frequently use a dam-break-generated bore to drive the swash on impermeable beds (e.g., Barnes et al, 2009;Kikkert et al, 2012;O'Donoghue et al, 2010;Yeh et al, 1989) and permeable beds (e.g., Kikkert et al, 2013;Othman et al, 2014;Postacchini et al, 2014), motivated by the close resemblance between a long wave that breaks in the surf zone before traveling as a fully developed bore toward the shoreline and a dambreak-generated bore. Solitary waves have also been used to study isolated swash events, motivated by questions of tsunami run-up (reviews by Synolakis and Bernard, 2006;Madsen et al, 2008) and motivated by observations that long waves on a beach often resemble a train of solitary waves (Peregrine, 1983).…”

Section: Introductionmentioning

confidence: 99%

An experimental study of the interaction of two successive solitary waves in the swash: A strongly interacting case and a weakly interacting case

Pujara

Liu

Yeh

2015

Coastal Engineering

View full text Add to dashboard Cite

The interaction of successive solitary waves in the swash zone have been studied using large-scale experiments with a simple bathymetry of a constant depth region, where the water depth was 1.72 m, and a plane beach, whose slope was 1:12. Two wave cases were considered where two successive solitary waves of the same height were generated one after the other so that the wave crests were separated by the effective wavelength associated with a single solitary wave. In the weakly interacting case, the swash period associated with a single solitary wave is smaller than the time period separating the successive wave crests, which leads to similar run-ups for the first and second wave, whereas in the strongly interacting case, the swash period associated with a single solitary wave is larger than the time period separating the successive wave crests, which leads to a significant reduction in the run-up of the second wave. The degree to which there is an interaction between the swash uprush of the second wave and the downrush of the first wave is found to be related to the solitary wave slope parameter, which predicts breaker type of the first wave. Previous data from literature are found to support this claim. Measurements of bed shear stress, bed pressure, and the free-surface displacement at a location near the stillwater shoreline are used to describe how the dynamics of the boundary layer differ when the downrush of the first wave meets the incoming second wave in both cases.

show abstract

Section: Introductionmentioning

confidence: 99%

An experimental study of the interaction of two successive solitary waves in the swash: A strongly interacting case and a weakly interacting case

Pujara

Liu

Yeh

2015

Coastal Engineering

View full text Add to dashboard Cite

show abstract

“…A conservative form of Equations (10) and (11), in line with the use of a conservative formulation for the NSWE system detailed in the following, is therefore not required. The HLES formulation explained above has been successfully tested and validated against experimental evidence in earlier works (e.g., [41][42][43]). …”

Section: The Nonlinear Shallow Water Equations: the Analyticsmentioning

confidence: 99%

“…The hydrodynamic numerical solver employed in the present work, which is described in detail and validated in [38] as well as through previous experiences with various configurations (e.g., [27,42,43,46,47]), is used to solve the conservative form (14) of the NSWEs and hence update the flow variables u, v and d in a time-marching procedure. The NSWE system (14) is preliminarily split up into two homogeneous, 1-dimensional systems and one "source" system, which are solved separately:…”

Section: The Nonlinear Shallow Water Equations: the Numericsmentioning

confidence: 99%

Waves and Currents at a River Mouth: The Role of Macrovortices, Sub-Grid Turbulence and Seabed Friction

Melito

Postacchini

Darvini

et al. 2018

Water

Self Cite

View full text Add to dashboard Cite

Abstract:Numerical experiments of wave-current interaction have been performed to investigate the evolution and dissipation of horizontal large-scale vortical structures generated by differential wave breaking and current shearing at river mouths. Specific focus is on the role played by turbulence of scales smaller than the water depth and by seabed friction on the dissipation of the mentioned macrovortices. The analysis reveals two regions of turbulence generation: at the river mouth, and along the curved seaward boundary of the shoal. In the latter zone, macrovortices are formed due to differential wave breaking induced by the sudden variation in water depth and enhanced by opposing currents which favour wave steepening. Such vortices are then advected towards the shore. Among the dissipative mechanisms, dissipation induced by seabed friction is deemed dominant, in particular in the most shallow waters of the shoal. Sub-grid turbulence dissipation, conversely, is more efficient offshore, although exerting some effect also over the shoal when supported by the continuous action of waves.

show abstract

“…In numerical and analytical studies of swash sediment transport, standard expressions are used to compute the sediment transport rate (e.g. Briganti, Dodd, Pokrajac, & O'Donoghue, 2012;Kelly, & Dodd, 2010;Postacchini, Brocchini, Mancinelli, & Landon 2012;Postacchini, Othman, Brocchini, & Baldock, 2014;Zhu, Dodd, & Briganti, 2012;Zhu, & Dodd, 2013a, 2013b, which, however, are not derived or calibrated for very shallow swash conditions. In fact, most, if not all, standard expressions for the sediment transport rate are either independent of or inversely proportional to the water depth (Zhu, & Dodd, 2013a).…”

Section: Introductionmentioning

confidence: 99%

Limitations of empirical sediment transport formulas for shallow water and their consequences for swash zone modelling

Pähtz

et al. 2016

Journal of Hydraulic Research

View full text Add to dashboard Cite

Volumetric sediment concentrations computed by phase-resolving swash morphodynamic models are shown to exceed unity minus porosity (i.e., the maximally physically possible concentration value) by up to factor 10 5 when using standard expressions to compute the sediment transport rate. An ad hoc limit of sediment concentration is introduced as a means to evaluate consequences of exceeding physically realistic concentration by standard expressions. We find that implementation of this ad hoc limit strongly changes the quantitative and qualitative predictions of phase-resolving swash morphodynamic models, suggesting that existing swash predictions are unreliable. This is because standard expressions inappropriately consider or ignore the fact that the shallow swash water depth limits the storage capacity of transported sediment.

show abstract

Sediment transport and morphodynamics generated by a dam-break swash uprush: Coupled vs uncoupled modeling

Cited by 28 publications

References 28 publications

An experimental study of the interaction of two successive solitary waves in the swash: A strongly interacting case and a weakly interacting case

An experimental study of the interaction of two successive solitary waves in the swash: A strongly interacting case and a weakly interacting case

Waves and Currents at a River Mouth: The Role of Macrovortices, Sub-Grid Turbulence and Seabed Friction

Limitations of empirical sediment transport formulas for shallow water and their consequences for swash zone modelling

Contact Info

Product

Resources

About