Ship hydrodynamics

Abstract

Ships have crossed the seven seas long before hydrodynamicists explained how this is possible. On the other hand, for the making of airplanes aerodynamic theory was indispensable and had to be developed simultaneously. That is, perhaps, why ship hydrodynamicists are flourishing more in secrecy than aerodynamicists. Yet, as a field of application of general fluid mechanics ship hydrodynamics is also interesting. As in aerodynamics most of the main methods are needed to describe the various aspects of the flow past a ship. Of course, supersonic flow or heat transfer are of no concern here; on the other hand, there is the free surface of the sea with waves in which theorists find much pleasure. As in aeronautics, the degree to which flow phenomena are comprehensible theoretically is very different. E.g., the intricate response of a ship in an irregular seaway can be calculated by potential theory in a surprisingly satisfactory manner, whereas the resistance of a ship in calm water is still to be found out experimentally by model tests since a theory for threedimensional, turbulent boundary layers is not yet known.