Numerical simulation of the flow field around the LPD vessel in straight ahead motion in calm water

Aim of this report is to present the job that has been done for investigating the flow around the vessel c2525; numerical simulations have been conducted by using the single phase level set RANSE solver developed at CNR-INSEAN. The solver is based on a finite volume discretization of the unsteady incompressible Navier-Stokes equations, with advection terms evaluated by means of a third order upwind scheme and diffusive fluxes discretized by a second order centered scheme. The test case considered is the flow around the model; one speed of advance is analyzed, namely 5Kn at full scale, which corresponds to a Reynolds number equal to Rn=2.11 10^6 (at model scale, scale factor lambda=35) and to a Froude number, Fn, is equal to 0.063. Due to the low Froude number, computations have been conducted under the assumption of flat free surface, i.e. a double model approach has been considered. The wave elevation (extremely small, as it will be shown) is evaluated from the Bernoulli equation applied on the flat surface itself. The model has been considered in its fully appended configuration, without the propeller and with the door opened and the landing platform dock fully flooded. The attitude is fixed, trim and sinkage conditions are taken from the experiments.