LINEAR MODELING OF OSCILLATING WATER COLUMNS INCLUDING VISCOUS LOSS

Wave-energy converters of the oscillating-water-column (OWC) type with pneumatic power take-off may be modelled by the so-called 'applied-pr essure' (or 'pressure-distribution') description. For wavelengths whic h are not too short, the alternative 'rigid-piston' description is als o applicable. The paper presents a transformation between the two desc riptions. A mechanical mass-spring equivalent model of the OWC is also presented together with analog electric circuit diagrams. Some accoun t of viscous energy loss is taken into consideration by introducing a mechanical loss resistance into the rigid-body description, and corres ponding analog electric circuit elements for both descriptions are inc luded. Some methods are presented to determine experimentally the mech anical loss resistance for a two-dimensional OWC. Copyright (C) 1996 E lsevier Science Limited.