Hydrodynamics of an oscillating water column seawater pump. Part II: tuning to monochromatic waves

Flume experiments with a scale-model of a wave driven seawater pump in mono chromatic waves are described. A tuning mechanism optimises the pump perfor mance by keeping it at resonance with the waves. The pumping process itself was found to de-tune the system because of the reduced gravity restoring f orce due to spilling in the compression chamber. A perturbation analysis of the pump equations shows that performance of the system can be increased b y optimising the shape of the pump intake to minimise losses due to vortex formation. An algorithm is derived, using a numerical model of the pump, wh ich accurately determines the required volume of air in the compression cha mber to induce resonance given variations in the wave frequency, the wave h eight and the tides. A sustainable development project to use a seawater pu mp to manage fisheries at a coastal lagoon in Mexico is described. (C) 2000 Elsevier Science Ltd. All rights reserved.