An investigation into the application of LES and DES for prediction of flow and forces around an IACC yacht keel and marine bodies

In this thesis, an approach into the applicability of Large Eddy Simulation (LES) and Detached Eddy Simulation (DES) for the prediction of forces and flow around marine bodies at high Reynolds number is presented. The main aim of the thesis was to investigate and assess the use of LES and DES based computational fluid dynamics applications as a tool for hydrodynamic prediction. A methodology for addressing the problem was followed based on mathematical models and numerical solutions translated into a three-dimensional commercial Computational Fluid Dynamics (CFD) code. Meshing strategy involved the use of adapted unstructured meshes with local refinement around key areas of the bodies. The CFD models based on LES and DES are validated against experimental measurements for three different bodies: a NACA 0012 section trefoil, a 6:1 prolate spheroid at angles of incidence and an assymetric America's Cup yacht keel. Quantitative comparisons included predictions of values of global force coefficients around the geometrics, pressure and friction coefficients on the surface, and wake analysis. Qualitative observation focused on flow generation near the bodies such as separation, velocity vectors. However, it is necessary to examine the problem further to have full confidence in their capabilities when applied to yacht hydrodynamics and more challenging flows.