Development of a Hybrid Lbm-potential Flow Model for Naval Hydrodynamics Developpement D’un Modèle Hybride Lbm-potentiel Pour L’hydrodynamique Navale

We report on the validation of a 3D hybrid model for naval hydrodynamics based on a perturbation method, where velocity and pressure are the sum of an inviscid flow with a viscous perturbation. The farto near-field inviscid flows can be solved with a BEM, based on potential flow theory and the near-field perturbation flow is solved with a NS model based on a Lattice Boltzmann Method (LBM). We give the model formulation and latest developments in LES turbulence modeling, including a wall model. We validate these by simulating flows over a flat plate for Re ∈ [3.7× 10; 1.2× 10], for which the plate friction coefficient agrees well with experiments. We also simulate the flow past a foil for Re = 3×106 and show good agreement of lift forces with experiments. Results obtained with the hybrid model are nearly identical to those of the LBM alone, but with a smaller computational domain, demonstrating the benefits of this approach.