Department of Mathematics Colloquium
|Higher speeds of fast marine vehicles can be
attained by utilizing aerodynamic lift. Drag reduction of slower cargo
vessels can be achieved by lubricating their hulls with air layers.
Ultra-fast planing multi-hulls (racing boats), wing-in-ground vehicles,
power-augmented-ram platforms, and air-cavity ships are examples of
marine craft with air assistance. The main technical problem in the
development and application of these concepts for marine transportation
is to ensure high performance and motion stability in a broad range of
operational regimes, including motions in water waves. Several
mathematical models for air-assisted marine vehicle concepts will be
discussed. They include the extreme-ground-effect theory, the
added-mass strip theory, and the method of hydrodynamic singularities.
Peculiarities of dynamics of ground-effect vehicles will be shown.
Simulation results will be presented for motions of a hydroplane,
including responses to initial perturbations, reactions to wind gusts,
and motions in head and following waves. A comparison between modeling
and experimental results for steady air cavities on a simplified model
hull will be also shown. Video clips of our self-propelled
radio-controlled models of amphibious marine craft will be demonstrated.