Behavior of Oil under Breaking Waves by a Two-phase SPH Model

TL;DR

This paper presents a two-phase SPH model based on GPUSPH to simulate oil dispersion under breaking waves, successfully capturing some key behaviors but with limitations due to wave complexity and setup.

Contribution

The paper introduces a novel two-phase SPH model for oil-water interactions under breaking waves, incorporating surface tension and validated against laboratory data.

Findings

Model predicts realistic oil drop shape changes during buoyancy.

GPUSPH reproduces pre- and post-breaking wave conditions well.

Oil dispersion predictions partially match laboratory observations.

Abstract

A two-phase Smoothed Particle Hydrodynamics (SPH) model has been developed on the basis of GPUSPH, which is an open-source implementation of the weakly compressible SPH method on graphics processing units, to investigate oil dispersion under breaking waves. By assuming that the multiple phases are immiscible, the two-phase model solves the same set of governing equations for both phases. Density in each phase is preserved by renormalization, and the harmonic mean of viscosities is used in the transition zone. Interfacial surface tension effect between the oil and the water is considered by a numerical surface tension model. The model is first used to simulate a single oil drop rising through still water. The numerical model predicts realistic shape change of the oil drop during the rising process caused by the buoyancy force. Next it is applied to reproduce a laboratory experiment on oil dispersion under breaking waves conducted at Johns Hopkins University. Several high-speed cameras were used to record the interaction between breaking waves and the oil. Comparison with the laboratory measurements shows that GPUSPH is able to reproduce well the pre- & post-breaking wave in the laboratory, however, oil dispersion predicted by GPUSPH only match part of the laboratory observation. Several factors (e.g., 3D & chaotic nature of breaking waves, numerical setup) cause the discrepancy.