For the development and design of the Mitsubishi Air Lubrication System (hereafter MALS),
which targets energy saving in ships, the utilization of simulation technology is essential. This
paper describes the key technology for the development of MALS, which is CFD-based prediction
technology for air bubble distribution around a hull, and also presents the frictional drag
reduction effect. It also presents a prediction technology for the pressure fluctuation of a propeller
that rotates in the bubbly flow, as well as a related technology for the prediction of gas-liquid
separation in a sea chest that is an engine cooling water suction port. The prediction accuracy of
these technologies has been verified and enhanced through verification in actual ship tests and
model tests, and therefore they are used as effective development and design tools. Also in the
future, MHI will continuously obtain data from the measurement results of actual ships and utilize
it for the performance enhancement of MALS.