Investigation on the Use of a Multiphase Eulerian CFD Solver to Simulate Breaking Waves

Abstract

The main challenge in CFD multiphase simulations of breaking waves is the wide range of interfacial length scales occurring in the flow: from the free surface measurable in meters down to the entrapped air bubbles with size of a fraction of a millimeter. This paper presents a preliminary investigation on a CFD model capable of handling this problem. The model is based on a solver, available in the open-source CFD toolkit OpenFOAM, which combines the Eulerian multi-fluid approach for dispersed flows with a numerical interface sharpening method. The solver, enhanced with additional formulations for mass and momentum transfer among phases, was satisfactorily tested against an experimental bubble column flow. The model was then used to simulate the propagation of a laboratory solitary breaking wave. The motion of the free surface was successfully reproduced up to the breaking point. Further implementations are needed to simulate the air entrainment phenomenon.

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

“…The model waveEuler treats a wave as a two-phase system composed of air and water. During the breaking process, this water-air system is characterized by a broad range of interfacial length scales which spans from the free surface (meters, at a laboratory scale) down to the small entrained air bubbles (fractions of a millimeter, [12]) as reported in [13]. In order to handle such different interfacial morphologies in the same spatial discretisation, waveEuler relies on a coupling between the Volume-of-Fluid (VOF) algorithm with the Eulerian multiphase approach.…”