Knowledge and methodology development for the analysis of air cavity ships – part 2

Research Project, 2017 – 2020

The Air Cavity Ship concept reduces the frictional resistance of the hull by replacing a large portion of the flat bottom with a shallow pressurized air chamber. Previous computational and experimental studies, both our own and international ones, have shown the ability of the air cavity system to reduce the hull resistance by up to 20%, i.e. 25000 MWh/year for a large ship, at ideal conditions, but they also indicated that this is far from the theoretical ideal (about 35%). Why this is the case is not clear, as well as the mechanisms that controls air release from the chamber. Current computational tools may improve understanding, but the problem is complex through its multifluid character and the large range of length scales in the flow, from the chamber length to small air bubbles. This project builds on previously developed knowledge and aims at developing robust simulation tools to predict net gain propulsive power and make it possible to support new concept development.