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
Numerical investigation of offshore oscillating water column devices
TL;DR: In this paper , the authors analyzed the hydrodynamic efficiency of offshore stationary OWC devices with different configurations through two-dimensional computational fluid dynamics simulations and showed that the best efficiency increases with the increase of the length of the bottom plate until the plate length is twice the chamber length.
Journal ArticleDOI
Vortex-induced piezoelectric cantilever beam vibration for ocean wave energy harvesting via airflow from the orifice of oscillation water column chamber
Xiao Zhen Du,Yu Wang,Haixiang Chen,Chicheng Li,Yi Han,Daniil Yurchenko,Junlei Wang,Hong Yan Yu +7 more
TL;DR: In this article , an ocean wave vortex-induced vibration piezoelectric energy harvester (Wavee-VIVPEH) is proposed to extract wave energy.
Journal ArticleDOI
Theoretically based correction to model test results of OWC wave energy converters to account for air compressibility effect
TL;DR: In this article , a new concept of linear turbine simulator aerodynamically equivalent to the orifice simulator is introduced in the theory, which combines linear theory in the frequency domain and hydrodynamic coefficients, together with air thermodynamics.
Journal ArticleDOI
The inclusion of non-linearities in a mathematical model for U-Oscillating Water Column wave energy converters
TL;DR: In this paper, a mathematical model for U-Oscillating Water Column (OWC) wave energy converters is developed and tested, based on the linear irrotational wave theory but is able to treat different nonlinearities related to the physical processes involved in the UOWC dynamics.
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