A free surface, finite-difference code on collocated grids, using the Slightly Compressible Flow formulation, is used for simulating turbulent flow around a Wigley hull. Two free-surface treatment techniques are compared in terms of accuracy and influence on the flow parameters. The runs were performed in standard conditions of Froude numbers and the results were compared against experimental and numerical results. The initial version of the code used an interface-tracking technique and two turbulence models (Large Eddy Simulation and Baldwin-Lomax). The numerical scheme was marched in time using the factorized Beam and Warming implicit method. The second version of the code uses an interface-capturing technique. For the time being, the code uses a fixed grid on which the kinematic free surface equation is solved. The grid is identical to the initial grid used in the first set of formulations. Other changes in the code were necessary, the most important being the switch of the time-marching method to a 2nd order, explicit Runge-Kutta. The results show good agreement with the experimental results.
Implicit gradient reconstruction (IGR) method for compressible flow simulation
