Multiphase Large Eddy Simulation of Wave Loading on a Vertical Cylinder: Towards Validated Simulation of Combined Wind and Wave Loading

Coastal structures in hurricane-prone regions are often elevated to reduce flooding damage; however, increased elevation exposes these structures to combined loading from large waves and potentially strong winds, as well as introduces an aerodynamic gap beneath the structure. Experiment-based understanding of this wind-wave interacting boundary layer is limited due to conflicting flow similitude scaling constraints. This work seeks to understand sensitivities and potential sources of error in a Large Eddy Simulation (LES) framework capable of directly modeling the combined action of wind and waves on elevated coastal structures. As a first step towards our objective, we use OpenFOAM with Volume-of-Fluid (VOF) methods to model wave loading on a vertical cylinder of nonbreaking, breaking, and broken nonlinear regular waves in still air and validate the numerical results through comparison with experimental data collected at Oregon State University's Large Wave Flume (LWF). We examine quasi-static, impact, and total forces, and explore sensitivity of these results to interface capturing scheme and other model choices. We will show that the LES results generally agree well with the experiment and present plans for further research exploring combined wind- and wave loading.