Numerical and experimental investigation of a planing Air Cavity Ship and its air layer evolution

The needs to reduce the frictional component of the resistance of a ship leads researchers to find new solutions. The air cavity solution seems to be one of the most promising one. Usually, it is very difficult with the experimental tests to understand the air distribution under the hull and the streamlines during the injection of air. The principal objective of this paper is evaluating the potentiality of the CFD approach in the study of Air Cavity Ships (ACS) for a planing yacht. The first part of paper describes the CFD evaluation of the resistance curves without air-injection. The second part deals with the injection of the air under the hull. In this case the boundary conditions are the results of the first campaign of simulations. A comparison between the experimental and CFD results is shown. An assessment of the streamlines and air distribution is proposed and an evaluation of the wetted and ventilated areas is conducted in order to understand the relation between the flow rate, the velocity of the hull and the air distribution. The results can be used for modifying the hull geometry in order to better accommodate the air layer.