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
A review on the progress and research directions of ocean engineering
TL;DR: In this article , the authors present a review of ocean engineering research over the last 50+ years with the aim to understand the technological challenges and evolution in the field, investigate whether ocean engineering studies meet present global demands, explore new scientific/engineering tools that may suggest pragmatic solutions to problems, and identify research and management gaps, and the way forward.
Journal ArticleDOI
Performance of a floating oscillating water column wave energy converter over a sloping bed
TL;DR: In this paper, the influence of bed slope on the hydrodynamic performance of a floating oscillating water column (OWC) device is investigated, and numerical computations are performed using the...
Journal ArticleDOI
Interaction of oblique waves with an Oscillating Water Column device
Ayrton Alfonso Medina Rodríguez,Alejandro Martínez Flores,Jesus Maria Blanco Ilzarbe,Rodolfo Silva Casarín +3 more
TL;DR: In this paper, the influence of oblique water waves on the OWC efficiency and the use of dual series relations to solve this type of boundary value problem was investigated. But the authors focused on the interference of the oblique waves and did not consider the effect of the wave angle of incidence.
Journal ArticleDOI
Performance enhancement for a dual-chamber OWC conceived from side wall effects in narrow flumes
Chen Wang,Yongliang Zhang +1 more
TL;DR: In this article , a dual-chamber OWC system composed of two 3D circular sub-units is examined under the framework of OpenFOAM, and the authors show that significant estimation errors in the capture width ratio may occur when the incident wave length is nearly equal to the flume width or the resonant frequency of water column is close to the wave frequency in a narrow flume.
Journal ArticleDOI
Mathematical modeling of marine structures
TL;DR: This paper aims to demonstrate the efforts towards in-situ applicability of EMMARM, as to provide real-time information about the physical properties of the E-modulus of the North Atlantic Ocean.
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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Hydrodynamic characteristics of an oscillating water column device
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