Journal ArticleDOI
Wave generation by an oscillating surface-pressure and its application in wave-energy extraction
TLDR
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.read more
Citations
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Journal ArticleDOI
An Experimental Study of Pile-Supported OWC-Type Breakwaters: Energy Extraction and Vortex-Induced Energy Loss
Fang He,Mingjia Li,Zhenhua Huang +2 more
TL;DR: In this paper, the importance of energy extraction and vortex-induced energy loss on the wave energy dissipation of pile-supported Oscillating Water Column (OWC)-type breakwaters were experimentally investigated.
Journal ArticleDOI
Wave power extraction by an axisymmetric oscillating-water-column converter supported by a coaxial tube-sector-shaped structure
TL;DR: In this article, an analytical theory was developed to study the effects of a coaxial tube-sector-shaped supporting structure on the conversion efficiency of a suspended, circular OWC converter.
Journal ArticleDOI
Hydrodynamic performance of an offshore-stationary OWC device with a horizontal bottom plate: Experimental and numerical study
TL;DR: In this paper, the hydrodynamic performance of an offshore-stationary Oscillating Water Column (OWC) device with an immersed horizontal bottom plate was investigated through both experimental tests and numerical simulations.
Journal ArticleDOI
Experimental and theoretical study of a cylindrical oscillating water column device with a quadratic power take-off model
TL;DR: In this paper, a cylindrical oscillating water column (OWC) device with a quadratic power take-off (PTO) model was studied experimentally and theoretically.
Journal ArticleDOI
Implementation and Verification of a Wave-to-Wire Model of an Oscillating Water Column With Impulse Turbine
TL;DR: In this article, a wave-to-wire model of an oscillating water column (OWC) is presented to estimate the power output of an OWC, as well as to test control strategies and algorithms allowing for development in the control of OWCs before physical deployment.
References
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Surface Waves
TL;DR: In this paper, the evanescent field structure over the wave front, as represented by equiphase planes, is identified as one of the most important and easily recognizable forms of surface wave.
Journal ArticleDOI
Wave-power absorption by systems of oscillating surface pressure distributions
TL;DR: In this article, the efficiency of energy absorption of a system of uniform oscillatory surface pressure distributions was derived based on linear water-wave theory and the results showed the close analogies which exist with theories for absorbing oscillatory rigid bodies and a number of new reciprocal relations for pressure distributions.
Journal ArticleDOI
On the Theory of the Wells Turbine
Luís M.C. Gato,A.F. de O. Falcão +1 more
TL;DR: In this article, the authors present an etude theorique du comportement thermodynamique de la turbine de Wells, a turbine a ecoulement axial adaptee a l'extraction d'energie a partir d'un energy alternatif, and obtention d'expressions for la forme d'ailette rendant maximal le rendement of the turbine.
Book ChapterDOI
Computer oriented algorithms for solving systems of simultaneous nonlinear algebraic equations
TL;DR: In this paper, the authors discuss the problem of solving N real equations in N real unknowns, and present the best algorithms for the various facets of the given system, such as getting into a region of local convergence from poor initial estimates, achieving guaranteed convergence to a root from anywhere within a specified region by suitably restricting the functions fi, using a technique in a vicinity of a root (local technique) which is fast, stable and which does not require the user to furnish derivatives of the function fi; and finally, obtaining additional roots of a nonlinear system without converging again to
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