Experimental study of the resistance of a hydrofoil supported watercraft (hysuwac)

A possible alternative to reduce fuel consumption on a ship is through energy efficiency. For this purpose, a hydrofoil supported watercraft (hysuwac) utilizes two hydrofoils, one installed near the bow and the other near the stern of the catamaran, to reduce the vessel's resistance. To investigate the effectiveness of the hydrofoils, CFD calculations were conducted in an earlier study. The purpose of this study is to provide experimental data to validate the CFD calculation results reported earlier for which towing tests were conducted at the Laboratory of Ship Hydrodynamics, ITS Surabaya, Indonesia. The ship model was made by using a three-dimensional print, which is then assembled into a ship model that meets the test requirements. The hydrofoil used has a NACA 641-212 section with an angle of attack of 4°. Twelve variations of towing tests were carried out with six variations of speed and two conditions, namely catamaran without and with foil system. A comparison between the CFD and experimental results shows that the CFD results are consistent with the experimental data. The minimum magnitude of percentage difference between the CFD results and experimental data is 1.14%, while the maximum magnitude of this is 16.79%. The observed difference is ascribed mainly to scale effects.