Ehsan Bahmyari

Despite the extensive research about stepped floats, their performance still cannot be evaluated definitively. Therefore, in the present project, we will study the effect of the geometry of transverse and longitudinal steps on the hydrodynamic performance of the high-speed float. In this study, an attempt is made to evaluate the types of stair forms and their geometry. The presence of a step under the body of a flying float, in the first place, prevents the concentration of pressure on the body and actually creates two pressure peaks in the pressure diagram. In the second place, by separating the current from the boat at the step and reconnecting it behind the step, it causes a decrease in the wet surface and as a result, a decrease in the resistance on the floating body. Simulating the float and adding stairs was done by Rhino 6 software. The 3D dynamic model of computational fluids is performed using finite volume discretization on 6-dimensional meshing. The free surface has been analyzed in three dimensions using the VOF model. Floating in the software has two degrees of freedom and is solved by the Everest technique for moving mesh. All the numerical simulations have been done with the help of the Star CCM Plus commercial code. The results obtained from the simulation show the effectiveness of body shape change solutions, such as the creation of transverse and longitudinal steps in stabilization, as well as reducing the resistance of the base model of the Cougar, which lacks a control surface and steps, at high speeds.