Showing papers on "Oscillating Water Column published in 1985"
TL;DR: In this paper, a two-dimensional analysis based on linear surface-wave theory is developed for an oscillating-water-column wave-energy device in water of arbitrary constant depth, and the results show that air compressibility can be important in practice, and its effects may in general be satisfactorily represented by linearization.
Abstract: A two-dimensional analysis, based on linear surface-wave theory, is developed for an oscillating-water-column wave-energy device in water of arbitrary constant depth. The immersed part of the structure is assumed of shallow draught except for a submerged vertical reflecting wall. Both the cases of linear and nonlinear power take-off are considered. The results show that air compressibility can be important in practice, and its effects may in general be satisfactorily represented by linearization. The analysis indicates that using a turbine whose characteristic exhibits a phase difference between pressure and flow rate may be a method of strongly reducing the chamber length and turbine size with little change in the capability of energy extraction from regular waves. It was found in two examples of devices with strongly nonlinear power take-off that the maximum efficiency is only marginally inferior to what can be achieved in the linear case.
286 citations
TL;DR: In this paper, the radiation coupling between all oscillators is represented by a partitioned matrix composed of the radiation admittance matrix for the pressure distributions, the radiation impedance matrix for oscillating bodies, and a radiation coupling matrix between the bodies and the pressure distribution.
138 citations
TL;DR: In this article, the effect of placing projecting sidewalls in front of the column was investigated, for different boundary conditions regarding the regions between the absorber and the channel walls, and it was shown that the projecting sidewall can improve the wave power absorption.
Abstract: Wave-power absorption by an oscillating water column in a channel is studied within linear theory, and for different boundary conditions regarding the regions between the absorber and the channel walls. Particular attention is given to the effect of placing projecting sidewalls in front of the column.
76 citations
TL;DR: In this paper, the authors describe the optimization of the power conversion chain and the engineering design considerations of an oscillating water column wave power device which would form part of a 2GW power station.
Abstract: This paper describes the optimization of the power conversion chain and the engineering design considerations of an oscillating water column wave power device which would form part of a 2-GW power station. Novel features of the principal device described include the multi-resonant concept, which considerably widens the frequency bandwidth response, and the use of the simple highly efficient Wells self-rectifying air turbine in the secondary power conversion stage. It is concluded that using established technology wave power stations comprising sea bed mounted reinforced concrete structures could produce power for as little as 1.3p per kW-hr after the initial capital repayment period and thus the economics are similar to that of hydro-electric power.
18 citations
TL;DR: In this article, the effects of the compressibility of air and inertia of an air turbine and electric generator on absorbed wave power are obtained by using the equivalent electric circuit concept, in which the equivalent floating body approximation is used, for absorbing wave power characteristics of an OWC device.
Abstract: An oscillating water column (OWC) wave power absorber is one of the most promising devices, as well as the Salter Duck and the Clam. This paper presents a simple prediction method, in which the equivalent floating body approximation is used, for absorbing wave power characteristics of an oscillating water column device. The effects of the compressibility of air and inertia of an air turbine and electric generator on absorbed wave power are obtained by using the equivalent electric circuit concept. Both the experimental and theoretical studies are carried out in this paper.
14 citations
TL;DR: A Wells self rectifying air turbine, coupled with a 100-W generator which produces an optimum level of damping to the water column for peak performance, has been designed and tested.
Abstract: This paper presents and discusses the results of the first stage of an ongoing research program to improve the design of wave powered navigation aids using the oscillating water column principle. Wave tank testing has shown that the heave motion of current tail tube buoys is the predominant feature of the hydrodynamic response. A Wells self rectifying air turbine, coupled to a 100-W generator which produces an optimum level of damping to the water column for peak performance, has been designed and tested.
4 citations
2 citations