M. Greenhow et Sp. White, OPTIMAL HEAVE MOTION OF SOME AXISYMMETRICAL WAVE ENERGY DEVICES IN SINUSOIDAL WAVES, Applied ocean research, 19(3-4), 1997, pp. 141-159
We present a mathematical model of the transient motion of a floating
body wave energy device, including memory and an impulsive term. The m
emory is calculated from the damping coefficients in the frequency dom
ain, and forms the kernel of an integral which is a component of the e
quation of motion to be solved numerically. The impulsive term is calc
ulated from the added mass. Convergence of both memory and impulsive t
erms in water of finite depth is considered. It is shown that the (mor
e general) transient memory model agrees with the usual added mass and
damping model for the large time behaviour of a body with linear exte
rnal constraints (power take-off), but that the full memory model is e
ssential for studying either transient motion or motion with non-linea
r constraints. An examination of the equation of motion in the time do
main suggests the possibility of implementing non-linear strategies su
ch as latching to improve the efficiency of the system. Results are pr
esented for a heaving hemisphere and two different truncated vertical
circular cylinders (with geometries given by the Swedish and Danish he
aving buoy devices). (C) 1997 Elsevier Science Ltd.