Characteristics of phase-averaged equations for modulated wave groups

Characteristics of phase-averaged equations for modulated wave groups

Klopman, G.
Petit, H.A.H.
Battjes, J.A.

Civil Engineering and Geosciences

Hydraulic Engineering

2000-10-01

The project concerns the influence of long waves on coastal morphology. The modelling of the combined motion of the long waves and short waves in the horizontal plane is done by phase-averaging over the short wave motion and using intra-wave modelling for the long waves, see e.g. Roelvink (1993). The evolution of the long-wave motion and the short-wave energy associated with slowly-modulated wave trains can be described by applying the average Lagrangian principle of Whitham (1974). The hydrodynamic part of the present version of the model (Reniers et al. 2000) solves a reduced set of equations for the surface elevation (mass transport velocity U and short-wave energy E, assuming the wave angular frequency w to be constant. This model describes the sub-harmonic triad interactions These equations are solved with a research version of the DELFT-3D model. The short-wave energy is assumed to propagate along fixed wave rays, which are computed at the start of a computation with the HISWA model. The the long-wave dynamics, as well as the short-wave energy propagation, sediment concentrations and morphodynamics are computed with the FLOW module of DELFT-3D.

long waves
wave grouping

http://resolver.tudelft.nl/uuid:6077ce28-b201-49b3-b805-f6575484ff44

TU Delft, Section Hydraulic Engineering

Report 09-00 for RIKZ (NCK study RKZ-140)

Institutional Repository

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© 2000 The Author(s)