Modeling of Wave-Current Interaction Using a Multidirectional Wave-Action Balance Equation

Abstract

This study presents an integrated numerical model to simulate wave deformation/transformation in tidal inlets or river mouths with ambient currents (e.g. tidal currents, river inflows) by carefully modeling the effect of wave-current interaction. A multidirectional wave-action balance equation is used to compute random/directional wave processes such as diffraction, refraction, shoaling, wave breaking, as well as wave-current interaction. This wave action model is coupled with a two-dimensional hydrodynamic model, the feedback effect of wave and current can be effectively simulated. This model is validated by simulating wave laboratory experiments in an inlet entrance, and waves and tidal currents in Grays Harbor, WA by using available field observation data in 1999. The capabilities of the wave model for simulating wave-current interaction and the corresponding breaking effect are confirmed in the study.

CMEMS downscaled wave operational forecast system

“…Physically, ocean currents can modify the relative speed of the air above the sea surface (relative wind effect) and change the absolute frequency of waves known as the Doppler shift. In addition, spatial variability of currents can modify the relative wave frequency and cause wave refraction, shoaling, and breaking that mimic bathymetric effects (Ding and Wang, 2011). The surface gravity waves, in return, can affect vertical mixing, surface and bottom stress experienced by currents.…”

Investigation of Morphological Changes in the Tamsui River Estuary Using an Integrated Coastal and Estuarine Processes Model

“…Wave-current interaction can be simulated by using the so-called wave-phase-resolving numerical models [24,25], which are usually computationally costly. For long-term and large-scale simulations, the phase-averaged models [26,27] are often used to provide engineering answers to coastal problems, such as dredging, erosion, flooding/inundation, etc.…”

“…Through many years of development, validation, and improvement, this model demonstrated its applicability to help engineering planning and design of coastal flood and erosion protection by considering complex hydrological and morphological conditions in estuaries [3,5,45]. The wave model of CCHE2D-Coast has the following major features: (1) It simulates deformation and transformation of irregular waves in coastal and estuarine conditions, including wave breaking, refraction, diffraction, and interaction of wave and current at river mouth [27]; (2) it considers the effect of wave roller due to breaking to compute more accurate radiation stresses to include the effect of varying vertical mean current structure in the surf zone. The sediment transport model takes into account the effect of combined waves and currents in an estuary [5].…”