NUMERICAL SIMULATION OF WAVE-DRIVEN FLOWS ON A MORPHOLOGICALLY EVOLVING BEACH

Ramy Marmoush,Ryan Mulligan

doi:10.9753/icce.v36v.waves.56

Abstract

Wave-driven flows in the nearshore zone are responsible for the erosion and transport of beach sediments, causing a continuous cycle of bathymetric change that is linked with changes to wave transformation and nearshore hydrodynamics. Numerical models have been used to investigate the evolving nearshore wave field corresponding to beach morphology change in field studies (e.g., Ruiz de Alegria-Arzaburu et al., 2013). In the present study, the non-hydrostatic wave-flow SWASH model (Zijlema et al., 2011) is applied to five laboratory cases to investigate the change in wave and flow fields corresponding to evolving beach morphology during a simulated storm event.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/LZQQuuiqsPY

Highlights

Wave-driven flows in the nearshore zone are responsible for the erosion and transport of beach sediments, causing a continuous cycle of bathymetric change that is linked with changes to wave transformation and nearshore hydrodynamics
PHYSICAL MODEL A three-dimensional physical model is implemented in a wave basin with a 20.0 m long sandy beach and a continuous steep slope of 1:5
The hydrodynamics are forced with a variation in wave energy over time and along the beach using a 10.7 m long wave paddle at the offshore boundary to simulate a passing storm along the coast

Summary

Introduction

Wave-driven flows in the nearshore zone are responsible for the erosion and transport of beach sediments, causing a continuous cycle of bathymetric change that is linked with changes to wave transformation and nearshore hydrodynamics. Directions (shoreward and seaward) to a width of 3.7 m and has a more uniformly distributed current speed of up to 0.45 m/s across the surf zone. PHYSICAL MODEL A three-dimensional physical model is implemented in a wave basin with a 20.0 m long sandy beach and a continuous steep slope of 1:5.

Results

Conclusion