Showing papers on "Wave power published in 1981"
TL;DR: A review of wave energy devices and hydrodynamic properties of idealized equipment for extracting power from waves is presented in this paper, where the governing equations involve fluid hydrodynamics applied to machines with zero forward speed which can absorb energy from the neighboring wave field.
Abstract: A review is presented of wave-energy devices and hydrodynamic properties of idealized equipment for extracting power from waves. The governing equations involve the fluid hydrodynamic theory applied to machines with zero forward speed which can absorb energy from the neighboring wave field. A mixture of waves of different amplitudes, periods, wavelengths, and directions with randomly distributed phases coexist at a given time a mathematical model of the sea surface assumes it to be an infinite superposition of wave trains of various amplitudes and frequencies. A theory was developed for the oscillation of two-dimensional energy-absorbing cylindrical sections which can be utilized for estimating hydrodynamic characteristics of fully three-dimensional ship hulls. Finally, three-dimensional wave-energy absorbers are represented by expressions in terms of the force amplitude, direction of motion, and the damping coefficient.
143 citations
TL;DR: In this article, an expression for the maximum mean power that can be absorbed by a system of oscillating bodies in waves under a global constraint on their motions is derived, and the particular case of a single half-immersed sphere is used to show how the 'point absorber' result predicting capture widths in excess of unity must be modified.
120 citations
TL;DR: In this paper, the transmission of flexural type waves through various discontinuities in the walls of cylindrical shells is investigated, and theoretical curves of transmission loss are obtained for different circumferential wave types, as functions of frequency.
91 citations
Patent•
11 Jul 1981
TL;DR: In this article, a wave power electricity generator was proposed to generate electricity by the wave power generator in which between protections is arranged a waterwheel in parallel with wave fronts, a wave sectioning plate is provided on the offing side, and a water level sectioning wall having a floating gate free to move is provided at the protection wall side, so that the waterwheel is continuously rotated by surf and backward waves.
Abstract: PURPOSE:To generate electricity by the wave power electricity generator in which between protections is arranged a water-wheel in parallel with wave fronts, a wave sectioning plate is provided on the offing side, and a water level sectioning wall having a floating gate free to move is provided on the protection wall side, so that the water-wheel is continuously rotated by surf and backward waves. CONSTITUTION:The water-wheel 4 is arranged at the approximately intermediate of the protections 2 through a water-wheel shaft 3 to permit the water-wheel 4 to rotate freely, the wave sectioning plate 5 is provided adjacent to it and on the offing side C, and the water level sectioning wall 6 having the floating gate 7 free to move is provided adjacent to it and on the coast side D. The surfs A and the backward waves B are sectioned by the wave sectioning plate 5, and the surfs A and the overrun sea water are sectioned by the water level sectioning wall 6. Thus, the contenuous surfs A can rotate the water-wheel 4, the surfs A would not be merged with successive surfs so that the water level over the water-wheel 4 can be kept at a certain level, and their backward waves B can also rotate the water-wheel 4, so that a dynamo 9 is continuously driven by the water-wheel shaft 3.
5 citations
Patent•
16 Oct 1981
TL;DR: In this article, the authors proposed a method to enable large capacity power to be generated by communicating through an air turbine through a comminication passage with a negative pressure stock chamber.
Abstract: PURPOSE:To enable large capacity power to be generated by communicating through an air turbine a positive pressure stock chamber connected to positive pressure type wave energy absorbers with a negative pressure stock chamber connected to negative pressure type wave energy absorbers CONSTITUTION:A positive pressure stock chamber 1 is communicated with a negative pressure stock chamber 2 by a comminication passage 3 wherein an air turbine 4 is disposed The positive pressure stock chamber 1 is connected to positive pressure type wave energy absorbers 6a, 6b and the negative pressure stock chamber 2 is connected to negative pressure type wave energy absorbers 6c, 6n A difference between pressures in the positive stock chamber 1 and the negative pressure stock chamber 2 may become great, thereby enabling wave power of large capacity to be generated
5 citations
Patent•
31 Jan 1981
TL;DR: In this article, the principle of lever action was used to drive a pump to lift sea water into a tank provided at a high place and utilize the sea water for the generation of electric power.
Abstract: PURPOSE:To allow a power of wave to enable a generation of electric power, by driving a pump with a power of wave doubled by the principle of lever action, permitting said pump to lift sea water into a tank provided at a high place and utilizing the sea water for the generation of electric power. CONSTITUTION:A piston rod 4 that makes a pumping action is linked to swinging plates 2 to which a wave receiving plate 3 is mounted, and a distance M between its link part B and pivotally supported part A is arranged considerably shorter than a distance N from the pivotally supported part A to the lower end of the wave receiving plate 3. In this way, a power of the wave can be doubled by the principle of lever action to drive a pump, thus capable of lifting sea water to a high place by a strong power, accordingly said sea water can be utilized to enable a generation of electric power.
4 citations
Patent•
12 Feb 1981
TL;DR: In this paper, the authors proposed a system that combines all known facilities, such as storage batteries, friction, wind power, vacuum, water pressure and suction, cooling to +4 deg. K, as well as the earth magnetic force.
Abstract: The electric energy generation method involves water and wind power, assisted by pumps, to drive the generating turbines. If used on ships the horizontal wind wheel can replace the ship's sails. The system can combine all known facilities, such as storage batteries, friction, wind power, vacuum, water pressure and suction, cooling to +4 deg. K, as well as the earth magnetic force. It can be also assisted by solar energy, sea wave power and natural (wind) or artificial air streams. The generative system has the advantage that it can be used under all weather conditions, on land and sea, and may be developed into a mobile system, with particular use on beaches and off-shore platforms.
3 citations
2 citations
Patent•
11 Jul 1981
TL;DR: In this paper, a swingable body having a float at its forward end to a rotating shaft, and connecting the rotating shaft with an output member through gear driving means for conveying only a rotational power directed in one direction is presented.
Abstract: PURPOSE:To convert the wave power efficiently into a mechanical rotational power, by securing a swingable body having a float at its forward end to a rotating shaft, and connecting the rotating shaft with an output member through gear driving means for conveying only a rotational power directed in one direction CONSTITUTION:The swingable body 6 having the float 7 at its forward end is attached to the rotational shaft 5 which is in turn connected with the output members through the gear driving means 11 conveying only a rotational power directed in one direction, a gear 17 and a shaft 18 Thus when the float 7 is moved up and down by the waves thereby the swingable shaft 5 is swinged, the gear 17 is rotated only in one direction by the gear driving means 11, so that the wave power can be economically and efficiently converted with a simple constitution into a mechanical rotational power
2 citations
Patent•
24 Aug 1981
TL;DR: In this paper, a double concentric shape was proposed to store and effectively utilize energies such as wave power, tidal current power, wind force and the like varying depending upon meteorological circumferences as hydraulic energies.
Abstract: PURPOSE:To store and effectively utilize energies such as wave power, tidal current power, wind force and the like varying depending upon meteorological circumferences as hydraulic energies. CONSTITUTION:A tidal power utilizing device is provided with a hydraulic piston driving part 2 driven by a buoy 1 floating on the sea surface, a connecting rod 3 which connects the buoy 1 to the hydraulic piston, a hydraulic outer side pipe arrangement 7 of the hydraulic piston driving part 2, a hydraulic inner side pipe arrangement 8, and the like. In this manner, by storing tidal power and the like as hydraulic power, effective utilization of energies varying depending upon meteorological circumstances is attempted, and the pipe arrangements are formed into a double concentric shape. The hydraulic outer side pipe arrangement 7 is formed into a low pressure return hydraulic pipe arrangement, and even when oil leaks, contamination in sea water is prevented.
2 citations
Patent•
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28 Nov 1981
TL;DR: In this article, a partition wall 5 and a top plate 8 are installed in the upper side of a float 7 and the cavity 10 is formed between them, where the air existing among the waves is introduced in the cavity and fed into the wind tunnel 18 by the pressure of the heads of waves.
Abstract: PURPOSE:To effectively utilize the wave energy to generate electricity, by continuously revolving an air turbine by blowing the air into a flat cavity by the waves, and feeding it into a wind tunnel from the air reservior of a cavity. CONSTITUTION:A partition wall 5 and a top plate 8 are installed in the upper side of a float 7 and the cavity 10 is formed between them. Connected with the cavity 10, the wind tunnel 18 is provided and the air turbine is installed in it. By this structure, the air existing among the waves is introduced in the cavity 10 and fed into the wind tunnel 18 by the pressure of the heads of waves, therefore, the air turbine is continuously revolved and electric power utilizing the wave energy is effectively generated.