Wave energy is one source of alternate energy that has fascinated man’s imagination throughout history yet has alluded his ability to tap it economically for domestic use. Considerable interest in harnessing wave energy exists today in a number of parts of the world, prompted to a large extent by the oil crisis of 1973. This paper examines several wave energy devices which are currently being investigated in the United Kingdom, Japan, Norway and the U.S.A. Each is briefly examined in respect to its operating principles, efficiency, advantages, weaknesses and state of development. The devices discussed are: (1) the Kaimei, the floating ship off the coast of Japan; (2) Salter’s nodding duck with its gyroscopic reference frame; (3) the Lancaster flexible bag; (4) the SEA CLAM version of a flexible bag; (5) the NEL oscillating water column fixed rigidly to the ground; (6) the Vickers terminator and attenuator versions of the oscillating water column; (7) the Norwegian use of a “harbour” with an oscillating water column used to increase the device’s range of frequency response; (8) the latching buoy of Norway; and (9) the Bristol cylinder. Also presented are the studies at the Technical University of Nova Scotia of a two hinged floating raft, the DAM ATOLL of U.S.A. origin and a version of an oscillating water column device designed to increase its spectral response.
Efficiency Assessment of an Amended Oscillating Water Column Using OpenFOAM
