DYNAMIC HEAVING MOTION OF GROUND EFFECT MACHINES
HYDRONAUTICS INC LAUREL MD
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The dynamics of simple ground effect machines undergoing heaving motion over a wavy surface is formulated. The equation of motion is a third order ordinary differential equation with the coefficients depending essentially on the mass flow into or out of the cavity under the machine and on the geometric characteristics of the machine. The response of machines traveling over a sinusoidal surface is derived as a function of the encounter frequency and mass flow coefficients. Then, mass flow coefficients are obtained for different types of machines. Peripheral jet machines without an exceptionally large volume of concave bottom are found to be stable in the heave mode. The reponses of both a peripheral jet machine and a plenum chamber machine are computed. The peak response of plenum chamber machines is generally higher than that of peripheral jet machines.
- Research and Experimental Aircraft