A Numerical and Physical Comparison of a Geometrically Simple Fixed and Floating Oscillating Water Column

2008 ◽  
Author(s):  
Rebecca K. Sykes ◽  
Anthony W. Lewis ◽  
Gareth Thomas
Keyword(s):  
Numerical Modelling ◽  
Water Column ◽  
Physical Modelling ◽  
Element Model ◽  
The Body ◽  
Internal Diameter ◽  
Oscillating Water Column ◽  
And Performance ◽  
Fixed Cylinder ◽  
Walled Cylinder

A truncated hollow vertical circular cylinder provides a useful conduit for analysing the behaviour and performance of an offshore Oscillating Water Column wave energy device. This paper presents the preliminary results from a numerical and physical modelling study of a fixed thin-walled and a floating thick-walled cylinder, together with the numerical modelling of a thick-walled fixed cylinder of the same internal diameter. Comparisons of the measured pressures internal to the column, and external to the body in the case of the floating model, are made with the predictions obtained using the numerical boundary-element model WAMIT. Body motions are also given for the floating model. The numerical modelling enables a comparison to be made between the diffraction pressure on a thin and thick walled cylinder of the same internal diameter.

HYDRODYNAMIC INVESTIGATION OF A NOVEL CONCEPT OF OWC TYPE WAVE ENERGY CONVERTER DEVICE

2021 ◽  
pp. 1-22
Author(s):  
Kourosh Rezanejad ◽  
Carlos Guedes Soares
Keyword(s):  
Water Column ◽  
Wave Theory ◽  
The Body ◽  
Hydrodynamic Performance ◽  
Bottom Plate ◽  
Linear Wave ◽  
Oscillating Water Column ◽  
Wave Direction ◽  
Linear Wave Theory ◽  
Novel Concept

Abstract The hydrodynamic performance of a novel and efficient concept of a floating Oscillating Water Column device has been investigated. The new concept consists of two chambers. These chambers are positioned on the upstream (fore chamber) and on the downstream (rear chamber) of the incident wave direction. The rear chamber acts mainly similar to a Backward Bent Duct Buoy system, while the design of the fore chamber follows conventional types of Oscillating Water Column systems with the harbour plates (bottom plate as well as side plates) elongated outside of the fore chamber. The primary efficiency of the devised concept has been investigated in the frequency domain. In this context, to solve the corresponding diffraction and radiation problems due to the influence of the air pressure inside the chambers as well as motions of the body, an in-house code has been developed in 2D using the Boundary Element Method based on linear wave theory. The obtained numerical results show that the introduced concept has advanced hydrodynamic efficiency in a broad range of waves.

Floating Moored Oscillating Water Column With Meshless SPH Method

2018 ◽  
Author(s):  
Alejandro J. C. Crespo ◽  
Matthew Hall ◽  
José M. Domínguez ◽  
Corrado Altomare ◽  
Minghao Wu ◽  
...  
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Coupled Model ◽  
Physical Modelling ◽  
Numerical Results ◽  
Mooring Line ◽  
Oscillating Water Column ◽  
Mooring Lines ◽  
Wave Energy Converters ◽  
Energy Converters

The meshless method called Smoothed Particle Hydrodynamics (SPH) is here proposed to simulate floating Oscillating Water Column (OWC) Wave Energy Converters (WECs). The SPH-based DualSPHysics code is coupled with MoorDyn, an open-source dynamic mooring line model. The coupled model is first validated using laboratory tests of a floating solid box moored to the wave flume bottom using four mooring lines interacting with regular waves. The numerical free-surface elevation at different locations, the motions of the floating solid box (heave, surge and pitch) and the tensions in the mooring lines are compared with the experimental data. Secondly, the coupled model is employed to simulate a floating OWC WEC moored to the sea bottom, while numerical results are also validated using data from physical modelling. The numerical results are promising to simulate floating OWC WECs. However, some discrepancies are noticed since the simulations presented in this work only consider a single-phase (water) so the full OWC WEC behaviour is only partially reproduced. Nevertheless, considering the aforementioned limitations, DualSPHysics can be used at this stage as complementary tool to physical modelling for a preliminary design of floating wave energy converters.

Hydrodynamic Investigation of a Novel Concept of OWC Type Wave Energy Converter Device

2019 ◽  
Author(s):  
Kourosh Rezanejad ◽  
Carlos Guedes Soares
Keyword(s):  
Water Column ◽  
Wave Theory ◽  
The Body ◽  
Hydrodynamic Performance ◽  
Bottom Plate ◽  
Linear Wave ◽  
Oscillating Water Column ◽  
Wave Direction ◽  
Linear Wave Theory ◽  
Novel Concept

Abstract In the present study, the hydrodynamic performance of a novel and efficient concept of a floating Oscillating Water Column device has been investigated. The new concept consists of two chambers that are placed in the upstream (fore chamber) and in the downstream (rear chamber) with respect to the incident wave direction. The rear chamber acts mainly similar to a Backward Bent Duct Buoy system, while the design of the fore chamber follows conventional types of Oscillating Water Column systems with the harbour plates (bottom plate as well as side plates) elongated outside of the fore chamber. The primary efficiency of the devised concept has been investigated in the frequency domain. In this context, to solve the corresponding diffraction and radiation problems due to the influence of the air pressure inside the chambers as well as motions of the body, an in-house code has been developed in 2D using the Boundary Element Method based on linear wave theory. The obtained numerical results show that the introduced concept has advanced hydrodynamic efficiency in a broad range of waves.

‘Man Is Ill Because He Is Badly Constructed’: Artaud, Klossowski and Deleuze in Search for the Earth Inside

2011 ◽  
Vol 5 (1) ◽  
pp. 18-34 ◽  
Author(s):  
Rick Dolphijn
Keyword(s):  
Performance Art ◽  
Holy Spirit ◽  
The Body ◽  
Deleuze And Guattari ◽  
The Earth ◽  
The Holy Spirit ◽  
Life Itself ◽  
Body Without Organs ◽  
Ways Of Thinking ◽  
And Performance

Starting with Antonin Artaud's radio play To Have Done With The Judgement Of God, this article analyses the ways in which Artaud's idea of the body without organs links up with various of his writings on the body and bodily theatre and with Deleuze and Guattari's later development of his ideas. Using Klossowski (or Klossowski's Nietzsche) to explain how the dominance of dialogue equals the dominance of God, I go on to examine how the Son (the facialised body), the Father (Language) and the Holy Spirit (Subjectification), need to be warded off in order to revitalize the body, reuniting it with ‘the earth’ it has been separated from. Artaud's writings on Balinese dancing and the Tarahumaran people pave the way for the new body to appear. Reconstructing the body through bodily practices, through religion and above all through art, as Deleuze and Guattari suggest, we are introduced not only to new ways of thinking theatre and performance art, but to life itself.

Comparison of the performance of oscillating water column devices based on arrangements of water columns

2020 ◽  
Vol 14 (3) ◽  
pp. 7082-7093
Author(s):  
Jahirwan Ut Jasron ◽  
Sudjito Soeparmani ◽  
Lilis Yuliati ◽  
Djarot B. Darmadi
Keyword(s):  
Wave Propagation ◽  
Water Column ◽  
Water Depth ◽  
Graphical Form ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Power Absorption ◽  
Water Columns ◽  
Single Column ◽  
Parallel Arrangement

The hydrodynamic performance of oscillating water column (OWC) depends on the depth of the water, the size of the water column and its arrangement, which affects the oscillation of the water surface in the column. An experimental method was conducted by testing 4 water depths with wave periods of 1-3 s. All data recorded by the sensor is then processed and presented in graphical form. The research focused on analyzing the difference in wave power absorption capabilities of the three geometric types of OWC based on arrangements of water columns. The OWC devices designed as single water column, the double water column in a series arrangement which was perpendicular to the direction of wave propagation, and double water column in which the arrangement of columns was parallel to the direction of wave propagation. This paper discussed several factors affecting the amount of power absorbed by the device. The factors are the ratio of water depth in its relation to wavelength (kh) and the inlet openings ratio (c/h) of the devices. The test results show that if the water depth increases in the range of kh 0.7 to 0.9, then the performance of the double chamber oscillating water column (DCOWC) device is better than the single chamber oscillating water column (SCOWC) device with maximum efficiency for the parallel arrangement 22,4%, series arrangement 20.8% and single column 20.7%. However, when referring to c/h, the maximum energy absorption efficiency for a single column is 27.7%, double column series arrangement is 23.2%, and double column parallel arrangement is 29.5%. Based on the results of the analysis, DCOWC devices in parallel arrangement showed the ability to absorb better wave power in a broader range of wave frequencies. The best wave of power absorption in the three testing models occurred in the wave period T = 1.3 seconds.

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