The Effect of Aircushion Division on the Motions of Large Floating Structures

The effect of aircushion division on the motions of large floating structures is studied by means of calculations based on a linear three-dimensional potential method. A linear adiabatic law is used to describe the air pressures inside the cushions. The water surface within the aircushions and the mean wetted surface are modelled by panel distributions representing oscillating sources. The behaviour of different types of aircushion supported structures is described and compared with that of a rectangular barge having the same dimensions. Successively, the aircushion theory, motion characteristics, wave frequency forces and moments, mean second order drift forces and surrounding wave fields are discussed. The results show that aircushions significantly influence the stability and behaviour of large floating structures.