Wave Induced Plume and Hydrodynamic Loads Over Vertical Circular Cylinder Piercing Surface – Numerical Investigation

Abstract

Offshore platforms and other marine structures are mainly composed of a group of circular cylinders. The hydrodynamics induced wave loads and the wave profile generated on the surfacepiercing circular cylinder are a significant issue in the structure life cycle. This project aims to develop a numerical model to accurately predict the calm sea behavior around a stationary circular cylinder. The stationary cylinder was partially immersed while encountering calm waves at 10 different Froude numbers (Fr). These flat waves were based on the free stream flow velocity U from 0.5 to 5 m/s with intervals 0.5. Three main key parameters of the flow behaviour were examined as follows: visual plume structure, wave impact loads, and distribution of pressure around the cylinder. The recommended Computational Fluid Dynamics (CFD) Software, namely STAR-CCM+ was employed, utilising the new technique of Adaptive Mesh Refinement (AMR) to accurately simulate the fluid relative motion over the cylinder. The results of this numerical study were validated with previously published experimental and numerical data and show good agreement in terms of the generated bow wave height and the drag coefficient. Due to the lack of the published data on the pressure distribution over the surface piercing cylinder, part of the result discusses the pressure coefficient around the cylinder. The research outcomes are beneficial to identify the key factors of calm waves' impact on the offshore cylinders with circular shape in order to reduce the generated loads and plume structure to attain efficient design.