A Coupled VOF-Eulerian Multiphase CFD Model to Simulate Breaking Wave Impacts on Offshore Structures

Abstract

Breaking wave-induced loads on offshore structures can be extremely severe. The air entrainment mechanism during the breaking process plays a not well-known role in the exerted forces. This paper present a CFD solver, developed in the Open-FOAM environment, capable of simulating the wave breaking-induced air entrainment. Firstly the model was validated against a bubble column flow. Then it was employed to compute the inline force exerted by a spilling breaking wave on a vertical cylinder in a 3D domain at a laboratory scale. Results showed that the entrained bubbles affected the magnitude of the force partially. Further analyses on the interaction of the bubble plume with the flow around the cylinder are needed.

Computational Fluid Dynamics Investigations of Breaking Focused Wave-Induced Loads on a Monopile and the Effect of Breaker Location

“…where t is the time, 0 ≤ α i ≤ 1 is the void fraction, ρ i the phase density, g the gravity acceleration, p is the pressure field assumed to be the same for all phases, and u i the grid scale phase velocity. Closure formulations for the effective stress tensor T e f f , for the momentum transfer M i and the mass exchange S i among bubbles were given in [10].…”

“…The air entrainment module of waveEuler is not used in the present study, but will be applied in the future work. Applications of waveEuler, where the Eulerian multiphase approach was actually used in combination with the VOF algorithm can be found in [10] and [15].…”

“…The aim of the present study is to verify and compare two different CFD models and to investigate the effect of breaker location on a monopile for breaking focused waves. The first model is built in [10] with a particular configuration of the libraries provided by the open-source package OpenFOAM (version 2.3.1) and it will be called waveEuler hereafter. The second one is the open-source REEF3D [11] .…”

Basic verification of a numerical framework applied to a morphology adaptive multifield two‐fluid model considering bubble motions

“…One possible combination is continuous water, continuous air, air bubbles, modeled as disperse air, and water droplets, modeled as disperse water, in the same computational domain. Tomiyama and Shimada 31 and Tomaselli and Christensen 32 proposed models, where both gas and liquid continuous phases share a single‐velocity field and every disperse phase is considered to have its own velocity field. Such a method is able to handle an arbitrary number of disperse phases, but only one pair of gas and liquid phases.…”