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
More filters
Journal ArticleDOI
An improved understanding of the natural resonances of moonpools contained within floating rigid-bodies: Theory and application to oscillating water column devices
TL;DR: In this paper, the fundamental interactions between waves, a floating rigid-body, and a moonpool that is selectively open to atmosphere or enclosed to purposefully induce pressure fluctuations are investigated, and an explicit hydrodynamic coupling term is included in the equations of motion.
Journal ArticleDOI
Hydrodynamics of an oscillating water column seawater pump: Part I: theoretical aspects
TL;DR: In this paper, a wave-driven seawater pump, composed of a resonant and an exhaust duct joined by a variable-volume air compression chamber, is studied, where the time dependent form of Bernoulli's equation, adapted to incorporate losses due to friction, vortex formation at the mouths and radiation damping, describes the pump behaviour.
Journal ArticleDOI
A tunable resonant oscillating water column wave energy converter
TL;DR: In this article, a wave energy converter (UREWEC) was constructed by attaching a U-tube to a traditional oscillating water column WEC, where the two sides of the U- tube are sloped.
Journal ArticleDOI
The influence of scale on the air flow and pressure in the modelling of Oscillating Water Column Wave Energy Converters
TL;DR: In this article, the authors investigated air compressibility effects during wave interaction with an Oscillating Water Column (OWC) Wave Energy Converter (WEC), including a thermodynamic equation for the air phase and potential flow equations for the water phase.
Journal ArticleDOI
Modelling the Interaction between Water Waves and the Oscillating Water Column Wave Energy Device
Utku Şentürk,Aydoğan Özdamar +1 more
TL;DR: In this article, the interaction between regular water waves and the oscillating water column (OWC) geometry is presented in a numerical wave tank, with the commercial CFD code Fluent, where the dynamic mesh feature and the VOF Model are used for wave generation and the water-air interaction, respectively.
References
More filters
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
Related Papers (5)
Hydrodynamic characteristics of an oscillating water column device
D. V. Evans,Richard Porter +1 more