The invention provides a propulsion system based on "thuniform" movement of
a foil member to achieve desired directional movement of a vehicle such as
an unmanned submarine type of vessel. A pair of foil members are mounted
to the vehicle body for reciprocating oscillating movement towards and
away from each other, creating forward movement due to the compression of
a fluid medium between the foil members and the expulsion of the
compressed fluid rearwardly of the foil members. Each foil member is
mounted to a pivot shaft for limited rotational movement with respect to
the vehicle body. Damping means are connected between each pivot shaft and
its associated foil member so that during operation of the propulsion
system damping torque will offset hydrodynamic loads imposed on the foil
members by the fluid medium. The damping means will in turn control the
pitch angle of the foil members during operation, meaning that a thrust is
generated for rigid foil members when moving at zero forward speed. The
propulsion system of the invention exhibits increased efficiency and
thrust in comparison to other such propulsion systems. The foil members
are mounted to the vehicle body in such a manner that the thrust vector
thereof can be directed through a full 360 degrees relative to the
vehicle, thereby achieving superb maneuverability when the vehicle is
provided with sets of the thrusters suitable located thereon.
