Browsing by Author "Bonneton, P."

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    A fourth-order compact finite volume scheme for fully nonlinear and weakly dispersive Boussinesq-type equations. Part II: Boundary conditions and validation
    (WILEY, 2007) Cienfuegos, R.; Barthelemy, E.; Bonneton, P.
    This paper supplements the validation of the fourth-order compact finite volume Boussinesq-type model presented by Cienfuegos et al. (Int. J. Numer. Meth. Fluids 2006, in press). We discuss several issues related to the application of the model for realistic wave propagation problems where boundary conditions and uneven bathymetries must be considered. We implement a moving shoreline boundary condition following the lines given by Lynett et al. (Coastal Eng. 2002; 46:89-107), while an absorbing-generating seaward boundary and an impermeable vertical wall boundary are approximated using a characteristic decomposition of the Serre equations. Using several benchmark tests, both numerical and experimental, we show that the new finite volume model is able to correctly describe nonlinear wave processes from shallow waters and up to wavelengths which correspond to the theoretical deep water limit. The results compare favourably with those reported using former fully nonlinear and weakly dispersive Boussinesq-type solvers even when time integration is conducted with Courant numbers greater than 1.0. Furthermore, excellent nonlinear performance is observed when numerical computations are compared with several experimental tests on solitary waves shoaling over planar beaches up to breaking. A preliminary test including the wave-breaking parameterization described by Cienfuegos (Fifth International Symposium on Ocean Wave Measurement Analysis, Madrid, Spain, 2005) shows that the Boussinesq model can be extended to deal with surf zone waves. Finally, practical aspects related to the application of a high-order implicit filter as given by Gaitonde et al. (Int. J. Numer Methods Engng 1999; 45:1849-1869) to damp out unphysical wavelengths, and the numerical robustness of the finite volume scheme are also discussed. Copyright (c) 2006 John Wiley & Sons, Ltd.
  • No Thumbnail Available
    Item
    A fourth-order compact finite volume scheme for fully nonlinear and weakly dispersive Boussinesq-type equations.: Part I
    (2006) Cienfuegos, R.; Barthelemy, E.; Bonneton, P.
    A high-order finite volume scheme is developed to numerically integrate a fully nonlinear and weakly dispersive set of Boussinesq-type equations (the so-called Serre equations) (J. Fluid Mech. 1987; 176:117-134; Surveys Geophys. 2004; 25(3-4):315-337). The choice of this discretization strategy is motivated by the fact that this particular set of equations is recasted in a convenient quasi-conservative form. Cell face values are reconstructed using implicit compact schemes (J. Comput. Phys. 1999; 156:137-180; J. Comput. Phys. 2004; 198:535-566) and time integration is performed with the help of a four-stage Runge-Kutta method. Numerical properties of the proposed scheme are investigated both, analytically using linear spectral analysis, and numerically for highly nonlinear cases. The numerical analysis indicates that the newly developed scheme has wider stability regions and better spectral resolution than most of the previously published numerical methods used to handle equivalent set of equations. Moreover, it was also noticed that the use of mixed-order strategies to discretize convective and dispersive terms may result in an important overall reduction of the spectral resolution of the scheme. Additionally, there is some numerical evidence, which seems to indicate that the incorporation of a high-order dispersion correction term as given by Madsen et al. (Coastal Eng. 1991; 15:371-388) may introduce instability in the system. Copyright (c) 2006 John Wiley & Sons, Ltd.
  • No Thumbnail Available
    Item
    Barred-beach morphological control on infragravity motion
    (2012) Almar, R.; Cienfuegos Carrasco, Rodrigo Alberto; Gonzalez, Eduardo; Catalán, P.; Michallet, H.; Bonneton, P.; Castelle, B.; Suarez, L.
    A conceptual analysis of the coupling between bars and infragravity waves is performed combining laboratory experiments and numerical modeling. Experiments are carried out in a wave flume with a barred profile. The Boussinesq fully-nonlinear model SERR1D is validated with the laboratory data and a sensitivity analysis is performed next to study the influence on the infragravity wave dynamics of bar amplitude and location, and swash zone slope. A novel technique of incident and reflected motions separation that conserves temporal characteristics is applied. We observe that changing bar characteristics induces substantial variations in trapped energy. Interestingly, a modification of swash zone slope has a large influence on the reflected component, controlling amplitude and phase time-lag, and consequently on the resonant pattern. Variations of trapped infragravity energy induced by changes of swash zone slope reach 25 %. These changes in infragravity pattern consequently affect short-wave dynamics by modifying the breakpoint location and the breaking intensity. Our conceptual investigation suggests the existence of a morphological feedback through the action of evolving morphology on infragravity structures which modulates the action of short-waves on the morphology itself.
  • Thumbnail Image
    Item
    Morphological changes in a cuspate sandy beach under persistent high-energy swells : Reriaca Beach (Chile)
    (2019) Agredano, Roberto; Cienfuegos Carrasco, Rodrigo Alberto; Catalan, P.; Mignot, E.; Bonneton, P.; Bonneton, N.; Martinez, C.
  • Thumbnail Image
    Item
    Recent advances in Serre-Green Naghdi modelling for wave transformation, breaking and runup processes
    (ELSEVIER, 2011) Bonneton, P.; Barthelemy, E.; Chazel, F.; Cienfuegos, R.; Lannes, D.; Marche, F.; Tissier, M.
    To describe the strongly nonlinear dynamics of waves propagating in the final stages of shoaling and in the surf and swash zones, fully nonlinear models are required. The ability of the Serre or Green Naghdi (S-GN) equations to reproduce this nonlinear processes is reviewed. Two high-order methods for solving S-GN equations, based on Finite Volume approaches, are presented. The first one is based on a quasi-conservative form of the S-GN equations, and the second on a hybrid Finite Volume/Finite Difference method. We show the ability of these two approaches to accurately simulate nonlinear shoaling, breaking and runup processes. (C) 2011 Elsevier Masson SAS. All rights reserved.
  • No Thumbnail Available
    Item
    Roller modelling in the context of undertow prediction
    (2005) Cienfuegos Carrasco, Rodrigo Alberto; Barthélemy, E.; Bonneton, P.
    In this paper we investigate the energy-based roller equations previously published by Stive and De Vriend (1994) and Dally and Brown (1995). Although these models differ by a factor of 2 in one of their terms, the same parameter values are commonly used to solve them. Our aim is to elucidate these discrepancies and to explore the physical adequacy of the roller models by using an inverse modelling technique based on undertow measurements. Comparison with Cox (1995) experimental data on regular waves propagating on a planar beach shows that a realistic contribution of potential energy in the roller equation should be included.