OpenFOAM predictions of hydrodynamics loads on full-scale TLP

Abstract

OpenFOAM is an open-source finite-volume solver in the public domain. In recent years, its use for fluid-flow simulations has grown very rapidly due to its flexibility and extensive capabilities. However, to date, its application in ocean engineering has been very limited. The main purpose of this paper is to evaluate this tool for use in this field. Simulations were hence performed of the flow field around a full-scale Tension-Leg Platform (TLP) in steady current at high Reynolds number. Of particular interest was assessment of OpenFOAM׳s ability to accurately predict the unsteady hydrodynamic loads due to vortex shedding. Turbulence was accounted for using the k−ε model. It was found that this model, which remains the model of choice in engineering practice, fails badly in this respect. A modification that has been shown to improve this model׳s performance in flows with vortex shedding was then implemented into OpenFOAM and checked against two benchmark flows namely around a single cylinder and around two cylinders in tandem. Application of the modified solver to the TLP flow convincingly demonstrates the suitability of this open-source tool, when used with the appropriate turbulence closure, for use in applications of interest to the ocean engineering community.