Advances in numerical modelling of swash zone dynamics

Briganti, Riccardo; Torres-Freyermuth, Alec; Baldock, Tom E.; Brocchini, Maurizio; Dodd, Nicholas; Hsu, Tian-Jian; Jiang, Zhonglian; Kim, Yeulwoo; Carlos Pintado-Pati�o, Jose; Postacchini, Matteo

Abstract

We present a comprehensive and critical review of work on the numerical modelling of swash zone processes between 2005 and 2015. A wide range of numerical models has been employed for the study of this region and, hence, only phase-resolving approaches (i.e., depth-averaged and depth-resolving models) are analyzed. The current advances in the modelling of swash zone processes are illustrated by comparing different numerical models against laboratory experiments of a dam-break-driven swash event. Depth-averaged and depth-resolving models describe well the swash flow for both coarse sand and gravel impermeable beach cases. Depth-averaged models provides a practical tool for engineering use, whereas depth-resolving models improve the flow description, especially for the backwash phase, with a significantly higher computational cost. The evolution and magnitude of bed shear stresses predicted by all models is reasonable when compared with laboratory estimates based on the log-law. However, differences between modelling approaches cannot be rigorously evaluated owing to the uncertainty in shear stress estimates while employing such approximation. Furthermore, small-scale processes, such as turbulence evolution, are investigated with depth-resolving models, finding differences between the two-dimensional and three-dimensional approaches. Numerical models allow us to investigate other processes such as beach morphology changes, the evolution of the turbulence coherent structures, and the infiltration/exfiltration effects on the swash flow. A discussion on the advantages and limitations of each model is presented. The future of swash zone modelling depends on the increase of the computational power and, more importantly, on the improvement of the current capability to obtain intra-wave measurements for model validation, calibration, and greater resolution of physical processes.

Citation

Briganti, R., Torres-Freyermuth, A., Baldock, T. E., Brocchini, M., Dodd, N., Hsu, T.-J., Jiang, Z., Kim, Y., Carlos Pintado-Patiño, J., & Postacchini, M. (2016). Advances in numerical modelling of swash zone dynamics. Coastal Engineering, 115, 26-41. https://doi.org/10.1016/j.coastaleng.2016.05.001

• Journal Article Type: Article
• Acceptance Date: May 4, 2016
• Online Publication Date: Jun 11, 2016
• Publication Date: Sep 1, 2016
• Deposit Date: Sep 10, 2018
• Journal: Coastal Engineering
• Print ISSN: 0378-3839
• Electronic ISSN: 0378-3839
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 115
• Pages: 26-41
• DOI: https://doi.org/10.1016/j.coastaleng.2016.05.001
• Keywords: Swash zone, Numerical modelling, Bottom boundary layer, Turbulence, Bed shear stress, Sediment transport, Beach morphodynamics
• Public URL: https://nottingham-repository.worktribe.com/output/1114040
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0378383916300692
• Related Public URLs: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84974569577&partnerID=40&md5=8ba089b1937a51c12d6dcc5cb2270c48