Theory for Absorption of Wave Power by a System of Interacting Bodies

1977 ◽  
Vol 21 (04) ◽  
pp. 248-254 ◽  
Author(s):  
K. Budal
Keyword(s):  
Incident Wave ◽  
Wave Power ◽  
Far Field ◽  
Incident Power ◽  
Power Absorption ◽  
Single Row ◽  
Plane Incident Wave ◽  
Absorbed Power ◽  
Field Velocity ◽  
Substantial Factor

Wave power absorption by a system of interacting bodies is analyzed within linear theory. A general expression for the wave power absorbed by the system, in terms of far-field velocity potentials, is derived. The optimum power absorption by a system of identical bodies from a plane incident wave is obtained. The theory is applied to various configurations of bodies oscillating in one or two modes. It is shown that the interaction between properly spaced bodies may raise the absorbed power per body by a substantial factor. It is also demonstrated that a single row of oscillating bodies may absorb 50 percent of the incident power if the bodies are operated in one mode and 100 percent if operated in two modes.

Radiation and scattering of water waves by rigid bodies

1971 ◽  
Vol 46 (1) ◽  
pp. 151-164 ◽  
Author(s):  
J. L. Black ◽  
C. C. Mei ◽  
M. C. G. Bray
Keyword(s):  
Surface Waves ◽  
Incident Wave ◽  
Water Waves ◽  
Variational Formulation ◽  
Rigid Bodies ◽  
Small Oscillation ◽  
Circular Cylinders ◽  
Wave Forces ◽  
Far Field ◽  
Plane Incident Wave

Schwinger's variational formulation is applied to the radiation of surface waves due to small oscillation of bodies. By means of Haskind's theorem the wave forces on a stationary body due to a plane incident wave are found using only far-field properties. Results for horizontal rectangular and vertical circular cylinders are presented.

scholarly journals Total wave power absorption by a multi-float wave energy converter and a semi-submersible wind platform with a fast far field model for arrays

2021 ◽  
Author(s):  
Peter Stansby ◽  
Efrain Carpintero Moreno ◽  
Sam Draycott ◽  
Tim Stallard
Keyword(s):  
Wind Turbine ◽  
Wave Energy ◽  
Radiation Damping ◽  
Wave Energy Converter ◽  
Wave Power ◽  
Far Field ◽  
Energy Converter ◽  
Power Absorption ◽  
Wave Energy Converters ◽  
Total Wave

AbstractWave energy converters absorb wave power by mechanical damping for conversion into electricity and multi-float systems may have high capture widths. The kinetic energy of the floats causes waves to be radiated, generating radiation damping. The total wave power absorbed is thus due to mechanical and radiation damping. A floating offshore wind turbine platform also responds dynamically and damping plates are generally employed on semi-submersible configurations to reduce motion, generating substantial drag which absorbs additional wave power. Total wave power absorption is analysed here by linear wave diffraction–radiation–drag models for a multi-float wave energy converter and an idealised wind turbine platform, with response and mechanical power in the wave energy case compared with wave basin experiments, including some directional spread wave cases, and accelerations compared in the wind platform case. The total power absorption defined by capture width is input into a far field array model with directional wave spreading. Wave power transmission due a typical wind turbine array is only reduced slightly (less than 5% for a 10 × 10 platform array) but may be reduced significantly by rows of wave energy converters (by up to about 50%).

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.

EXPERIMENTAL STUDY ON WAVE POWER CHARACTERISTIC OF BREAKWATER WITH LOW CREST DISSIPATING BLOCKS TO SHARP-ANGLED INCIDENT WAVE

2019 ◽  
Vol 75 (2) ◽  
pp. I_355-I_360
Author(s):  
Eiichirou SUGI ◽  
Hisanori YOSHIMURA ◽  
Kenta KAKOI ◽  
Aoi ENOMOTO ◽  
Takanori MORIKAWA ◽  
...  
Keyword(s):  
Experimental Study ◽  
Incident Wave ◽  
Wave Power ◽  
Power Characteristic

scholarly journals Боковой перенос энергии при возбуждении плазмонов терагерцовой волной в периодической пространственно несимметричной графеновой структуре

2019 ◽  
Vol 53 (9) ◽  
pp. 1189
Author(s):  
Д.В. Фатеев ◽  
К.В. Машинский ◽  
И.М. Моисеенко ◽  
В.В. Попов
Keyword(s):  
Incident Wave ◽  
Radiation Power ◽  
Power Conversion ◽  
Incident Radiation ◽  
Terahertz Wave ◽  
Wave Power ◽  
Excitation Condition ◽  
Maximum Conversion

AbstractThe power conversion of a terahertz wave normally incident on a periodic graphene structure to propagating-plasmon power is theoretically studied. The conditions of the maximum conversion of the incident radiation power to the propagating-plasmon power and excitation condition of unidirectional traveling plasmon are determined. It is found that up to 15% of the incident wave power can be converted to propagating-plasmon power.

scholarly journals A Broadband Ultrathin Nonlinear Switching Metamaterial

2017 ◽  
Vol 6 (2) ◽  
pp. 64
Author(s):  
E. Zarnousheh Farahani ◽  
S. Jarchi ◽  
A. Keshtkar
Keyword(s):  
Incident Wave ◽  
Optimization Method ◽  
Resonant Mode ◽  
Unit Cell ◽  
Incident Power ◽  
Full Wave ◽  
Effective Impedance ◽  
Nonlinear Simulations ◽  
Switching Property ◽  
Transmission And Reflection

In this paper, an ultrathin planar nonlinear metamaterial slab is designed and simulated. Nonlinearity is provided through placing diodes in each metamaterial unit cell. The diodes are auto-biased and activated by an incident wave. The proposed structure represents a broadband switching property between two transmission and reflection states depending on the intensity of the incident wave. High permittivity values are presented creating a near zero effective impedance at low power states, around the second resonant mode of the structure unit cell; as the result, the incident wave is reflected. Increasing the incident power to the level which can activate the loaded diodes in the structure results in elimination of the resonance and consequently a drop in the permittivity values near the permeability one as well as a switch to the transmission state. A full wave as well as a nonlinear simulations are performed. An optimization method based on weed colonization is applied to the unit cell of the metamaterial slab to achieve the maximum switching bandwidth. The structure represents a 24% switching bandwidth of a 10 dB reduction in the reflection coefficient.

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