Preliminary scantling design of Aerodynamically Alleviated Marine Vehicles (AAMV)

For very high speed marine crafts the aerodynamic forces can become of the same order of magnitude as the hydrodynamic ones, especially for small vessels. Although these forces can lead to instability issues in some cases, they can also offer a new range of possibilities to sustain the weight of the craft. The vessel can be equipped with aerodynamic lifting surfaces in order to alleviate the weight of the vehicle, leading to a lower effective displacement, hence lower resistance and required power. The estimation of the total weight of the vehicle and of its distribution is of paramount importance, since it strongly affects the whole design process. Due to the lack of commercially established AAMV configurations, and due to the substantial differences between AAMV and other fast vehicles, regressions based on historical data derived from present and past vehicles are not available. The proposed approach is therefore based on the High Speed Craft Code and on first principles of structural engineering, considering both global and local behaviour of structural components. The developed procedure works out an estimate of the weight of the structure using as input data only the main characteristics of the AAMV under design and it represents a starting point in the scantling design of an AAMV in the first steps of the design spiral.