Design Trade-off Analysis for High Performance Ship Hull with Air Plenums

Multi-hull designs with captured air plenums have potential benefits in reduced resistance, better shock mitigation, and improved seakeeping performance. We propose to extend our proprietary CFD software, 3DYNAFSc, to the study of complex ship hulls withair plenums. 3DYNAFSc has been very successful in many unsteady free surface problems such as simulations of ship generated waves, wave-ship interactions on beaches, cavitation on propeller blades and hydrofoils, bubble behaviors in vortex flows, andunderwater explosion bubbles and their interaction with nearby structures. This 3-D non-linear Boundary Element Method code has the advantage that it is coupled with an Unsteady Reynolds-Averaged Navier-Stokes equation solver. The coupled 3DYNAFSc will beused to study the conditions necessary to generate a stable air cavity, while the stand alone 3DYNAFSc will be used in the initial study on hull form parameters. The code will enable us to understand the fundamental hydrodynamics of the hull form,including the ventilated cavity behaviors, the effect of cavity on the ship generated waves, wave-making and total resistance, and the optimum geometry of the air cavity boundary. We will perform a trade-off analysis among combinations of the hull formparameters by comparing hydrodynamic pros and cons of various designs. The developed code will be a useful tool to design complex hull forms including air plenums. These hull forms are expected to have wide applications in the naval and commercialsectors. The technology is potentially applicable to any fast ships such as small boats, cruisers, and possibly containers.