Weakly nonlinear theory for dispersive waves generated by moving seabed deformation. (25th April 2022)

• Record Type: Journal Article
• Authors: Michele, S.; Renzi, E.; Borthwick, A.G.L.; Whittaker, C.; Raby, A.C.
• Is Part Of: Journal of fluid mechanics. Volume 937(2022)
• Publication Date: 2022-04-25
• Subjects: wave-structure interactions -- coastal engineering; Fluid mechanics -- Periodicals; 532.005
• DOI: 10.1017/jfm.2022.94
• Languages: English
• ISSNs: 0022-1120

Abstract

Abstract: Abstract : We present a weakly nonlinear theory for the evolution of dispersive transient waves generated by moving seabed deformation. Using a perturbation expansion up to second order, we show that higher-order components affect mostly the leading wave and the region close to the deforming seabed. In particular, the leading wave in the nonlinear regime has higher crests and deeper troughs than the known linear solution, while the trough that propagates together with the moving seabed exhibits pulsating behaviour and has larger depth. We also validate the analytical model with experimental data and obtain good agreement between both approaches. Our results suggest a need to extend existing models that neglect the effects of wave dispersion and higher-order components, especially in view of practical applications in engineering and oceanography.