Numerical study on the influence of chord length of the foil and pipe diameter on winged air induction pipe optimization toward drag reduction

Drag reduction on the ship with an air lubrication method using microbubble started since the late 19th century. However, its application in industry obstructed because the net power-saving only reach 0-5% in the consequences of the energy needed by the air compressor to blow the air to the keel of the ship. A new device named Winged Air Induction Pipe (WAIP) uses the negative pressure produced by angled hydrofoil to suck atmospheric air into the water generating bubble without compressor needed. Interaction between the diameter of the pipe and the hydrofoil chord length influence the drag reduction occurred. The Computational Fluid Dynamics (CFD) approach by 'volume of fluid' model and SST k-ω turbulence closure model on 2D boundary condition, used to observe how these two variable affects the result. In the discussion, the correlation between those variables gives the maximum efficiency to the ship. On the optimum range, drag reduction can reach 9.5%.