2D numerical contributions for the study of non-cohesive sediment transport beneath tidal bores

Yoga Satria Putra (1, 2) , Anthony Beaudoin (1, 2) , Germain Rousseaux (1, 2) , Lionel Thomas (1, 2) , Serge Huberson (1, 2)

1 PPrime [Poitiers] - Institut Pprime [UPR 3346]
2 HydEE - Hydrodynamique et écoulements environnementaux [Institut Pprime]

2D numerical simulations of tidal bores were obtained using the OpenFOAM CFD software to solve the Navier--Stokes equations by means of the Finite Volume Method by applying a LES turbulence model. The trajectories of non-cohesive sediment particles beneath tidal bores were estimated using a tracker method. Using the fourth order Runge--Kutta scheme, the tracker method solves the Maxey and Riley equations, which requires the knowledge of the velocity field at time t. From 2D numerical simulations of tidal bores, we proposed a classification of tidal bores with respect to the Froude number Fr(or rthe ratio of water depths). For a Froude number 1 1.57(r>1.75), the tidal bore is totally breaking. Thenumerical results of trajectories of non-cohesive sediment particles are similar to the type of trajectories given by the analytical model proposed by Chen et al. (2012) with some modifications to take into account the effects of gravity, elevation, and attenuation. Theparameters of modified Chen's model, β1, β2and β3, are linearly proportional to the Froude numberFr. This is because the level of turbulence for undular tidal bores is low. The flow induced by anundular tidal bore is not complex. This physical phenomenon is quasi linear. Theparameter β1, related to the front celerity of the undular tidal bore, decreases when the Froude number Frincreases. Theparameter β2, related to the elevation, increases when the Froude number Frincreases. And the parameter β3, related to the attenuation of thesecondary waves, increases when the Froude number Frincreases.

Mots clés: Sediment transport; Maxey--Riley equations; Tracker method; Tidal bore; Froude number; Ratio of water depths; OpenFoam

Domaines: Mécanique des fluides [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]; Physique Quantique [quant-ph]; Acoustique [physics.class-ph]; Biomécanique [physics.med-ph]; Matériaux; Polymères; Acoustique [physics.class-ph]; Automatique / Robotique; Electromagnétisme; Milieux fluides et réactifs; Energie électrique; Thermique [physics.class-ph]; Vibrations [physics.class-ph]; Physique mathématique [math-ph]

Yoga Satria Putra, Anthony Beaudoin, Germain Rousseaux, Lionel Thomas, Serge Huberson. 2D numerical contributions for the study of non-cohesive sediment transport beneath tidal bores. Comptes Rendus Mécanique, 2019, 347 (2), pp.166-180. ⟨10.1016/j.crme.2018.11.004⟩. ⟨hal-02282788⟩