
Second, consider the 'atoll' part of the name. When it has the proper shape, the submerged dome of an atoll will cause approaching waves to spiral in towards its center. This spiral bending is called wave refraction. Now let's say that the diameter of the atoll is one mile. Approaching the atoll is a wave whose crest is, say, 1,000 miles in length. Some part of that length will be affected by the atoll, and will keep bending towards the atoll until it hits the center. The center of the atoll will receive the total energy of one mile's worth of wave. That is to say, the energy received by the atoll is equal to the energy present in the length of wave equal to the diameter of the atoll. Now the wave itself is nothing but energy—a pulse traveling across the ocean—so in receiving the energy contained in a one mile segment of the thousand mile wave, the atoll has captured one mile's worth of that wave.
This is the basic principle of DamAtoll as an ocean wave energy concentration device.
Picture Source.


An ocean wave is always half potential energy and half kinetic energy so long as it is propagating in deep water. As the wave enters shallower water, this proportion changes. The kinetic portion of the wave's energy becomes greater as the water becomes shallower. Conversely, the potential energy decreases. Finally, the wave's shape changes, its front side becoming steeper until it becomes completely vertical—a moving wall of water. At this point, its energy is nearly all kinetic. This wave configuration is unstable, and the wave breaks into a churning turbulence. This turbulance converts the kinetic energy into heat, so the wave water is a little warmer as it returns to the ocean. Picture Source.


A vortex is a natural swirling motion in any fluid such as water or air. If there is a hole in the center of an atoll with the proper shape, a vortex will form in that hole because the approaching waves are spiralling in towards the atoll's center. In this way, an atoll (if the reader can stomach yet one more pun) adds a special twist to the atoll's natural transformation of the wave's potential energy to kinetic energy. The really nice feature of vortexes is that very little energy is lost in them: they are, in a very real sense, fluid flywheels. DamAtoll, a
sea wave power station,
uses the kinetic energy of this vortex to power a turbine generating electricity. Picture Source.


DamAtoll functions as an artificial atoll, bending incoming waves and focussing their energy as they spiral into the center. Vanes at the center guide the incoming spiralling waves and directs the resulting vortex into a shaft. The whirling water in the vortex transfers its energy to a mechanical component, a shaftmounted turbine, which then runs a generator to create electrical energy. The shaftmounted turbine is the only moving part in this beautifully and elegantly simple design. Click here to see a video of working model of DamAtoll. In a fullscale prototype of this
ocean wave power station,
real boats will replace the toy boats, which L.S. Wirt stole from his grandsons. Picture Source.


Click here to see an html version of the patent. Click here to see commentary on DamAtoll by John Isaacs at the First Symposium on Wave Energy Utilization, held at Gothenburgh, Sweden. Click here to see an excerpt from the Advanced Techniques chapter of Michael E. McCormick's book, Ocean Wave Energy Conversion. Click here to see various other articles, books, and links to resources on the web discussing DamAtoll. Click here to see the Abstract, Table of Contents, and List of Figures of an article working out the mathematics describing the optimal shape of the artificial atoll that will result in the greatest efficiency in conversion from wave energy to electrical energy.


The world's energy requirements. Alternative energy clearly a necessity. Picture Source.


Humor may not be the first thing you associate with an
ocean wave power station.
Nonetheless, humor and brilliant technical inventions sometimes spring from the same source in the inventive mind. Click here to see some DamAtoll related humor, starting with the name itself, DamAtoll (pun definitely intended). Picture Source.


The mathematical principles explaining how atolls cause waves to refract were first worked out by the brilliant oceanographer Robert S. Arthur while he was still a graduate student at Scripps and under contract with the navy during the second World War. These mathematical principles form the basis of DamAtoll. Click here to see Arthur's classic paper, "The Effect Of Islands On Surface Waves." As noted by Arthur, the ancient Polynesians were aware of many of the same principles for which Arthur provided a mathematical description. Click here to see a discussion of their navigational charts composed of sticks representing islands, currents, and waves. Picture Source.

For the rightshaped atolls, the waves always spiral towards the center, as we have seen. For a number of years, we have been working on deriving the
mathematically optimal shape of the dome.
This work is of considerable mathematical interest, and will prove crucial when the time comes to build a fullscale prototype of damatoll.
This is the work that will get us furthest towards our goal of achieving 50% efficiency in extracting ocean wave energy and converting it to electrical energy. An abstract of the math is published here. (next)

Click on any of the following topics that may catch your eye
Best And Most Concise Description Of DamAtoll
The damndest thing that ever came out of an acoustics lab
Fermat's Principle
The Patent for DamAtoll is now in the public domain
The Name DamAtoll Tells How It Extracts Ocean Wave Energy
DamAtoll An Amalgam Of the Concepts Dam And Atoll
Dams And Kinetic, Potential, and Mechanical Energy
River As Kinetic Energy
Kinetic Energy Transformed To Potential Energy
Potential Energy Transformed Back To Kinetic Energy
Kinetic Energy Turned Into Mechanical Energy
An Atoll Bends And Refracts The Approaching Wave
Wave Velocity
Wave Refraction
When the submerged atoll is domeshaped, it refracts the wave path to its center
The exact shape of the atoll's dome is critical
the atoll acts as a kind of lense concentrating the wave energy
A Wave's Potential Energy Gets Changed To Kinetic Energy By An Atoll
A wave is nothing but energy
Waves And Potential And Kinetic Energy
A deepwater ocean wave is always half potential and half kinetic energy
Wave is all kinetic energy when it breaks on the center of the atoll
Changing A Wave's Kinetic Energy To Mechanical Energy By Means Of A Vortex
Vortex
Vortex is a fluid flywheel
DamAtoll, Vortex, Guide Vanes
This in sum is how DamAtoll works
Smoothing out the succession of wave pulses
Advantages Over The Other Ocean Wave Energy Extraction Devices
DamAtoll has only one moving part
Thus DamAtoll loses no energy in monkey motion
Monkey motion
Competing Ocean Wave Energy Extraction Devices are monkey motion machines
Energy Efficiency
Diffuser Important To Energy Efficiency
Mathematically Optimal Shape Of Dome Crucial To Energy Efficiency
A Future So Bright For Ocean Systems You Will Need Sunglasses
The Patent for DamAtoll is now in the public domain
The Opportunity
Leslie Wirt is available for lectures
Leslie Wirt offers consulting services
Video of working scale model of DamAtoll
DamAtoll Patent
Michael McCormick's Comments On DamAtoll
John Isaac's Comments On DamAtoll
Links To Books, Articles, And Web Sites Mentioning DamAtoll
Excerpts From Scattering And Absorption Of Surface Waves By Arthur's Island
Future Prospects For DamAtoll
DamAtoll Humor
DamAtoll_History
About the inventor of DamAtoll, Leslie S. Wirt
Contact Leslie Wirt

Next: The Opportunity

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