THE RAM AUGMENTED CATAMARAN

This paper introduces a new vehicle concept that addresses many of the difficult problems that have hindered the rapid development of many aerodynamically and aerostatically supported advanced marine vehicles. In this vehicle concept, very narrow stepped side hulls contain a rearward-flowing cushion of air between themselves and under a relatively high length to beam ratio hull. The source of the flowing cushion is a thick jet emanating from a slot across the leading edge of the craft. At the rear of the craft, the air escapes under a simple flap to provide thrust. This paper is an approximate theoretical study of the sizing, optimisation, and potential performance of such a craft. The paper references open-source literature supporting all the key assumptions. It is concluded that the Ram Augmented Catamaran can roughly match the aero-hydrodynamic performance of the corresponding hovercraft. Major potential advantages include the simple shape, the convenient machinery arrangement, absence of flexible skirts in contact with the water, and elimination of wave-pumping degradation of ride quality and performance.