A generalised fully unsteady hybrid RANS/BEM Model For Marine Propeller Flow Simulations

A generalised hybrid RANSE/BEM model for the analysis of hull/propeller interaction in ship hydrodynamics problems at reduced computational cost is presented. Akin to standard hybrid RANSE/BEM models, the coupling between viscous and inviscid- flow solvers is based on a volume-force/effective-inflow approach. The generalization consists in coupling a time-accurate solution by BEM of the unsteady flow around the rotating propeller with the solution of the surrounding viscous-flow by unsteady RANSE to account for transient-flow propeller perturbation. The methodology is validated through numerical applications to a simple case study describing a propeller in uniform flow conditions. Numerical results by the proposed hybrid RANSE/BEM model are compared with results by full-RANSE simulations and the capability of the methodology to correctly describe transient propeller flow perturbation to a surrounding viscous flow is investigated.