Wave Energy - Science topic

Respected Farhad Vedad

I do agree with You, Your insightful response highlights the necessity of considering space as a complex, dynamic entity rather than a simple, homogeneous medium. By recognizing that space can have varying refractive indices and properties as described by relativity, we understand that photons and electrons may interact with their environment in unique ways, influencing their diffraction and behavior. This perspective challenges the traditional wave-particle duality and underscores the importance of environmental context in studying physical phenomena. Just as in social sciences, where individual behavior is shaped by surroundings, particle behavior is also deeply influenced by the structure of space, encouraging a more holistic and integrated approach to understanding the natural world.

Dear friend Ismail Abbas

Alright, let's break this down.

If the frequency of electromagnetic waves (EMW) practically hit zero, you'd Ismail Abbas enter tricky territory. It's like navigating a minefield, with each step needing careful consideration.

Here's the deal:

1. **Classical EM Theory**: In this theory, wave energy flows continuously. So, if the frequency approaches zero, the energy remains continuous. However, this doesn't automatically make the energy of the photon continuous.

2. **Quantum Mechanics (QM)**: Now, in the quantum world, things get quantized. Energy is discrete, split into packets called photons. According to QM, even if the frequency is near zero, the energy of the photon remains quantized.

So, it boils down to which theory you're Ismail Abbas using.

- If we're rolling with QM, the answer is a solid no. Photons need positive momentum, which means they need positive frequency.

- But in the classical EM world, the answer could be yes, yet it's a bit tricky. The wave energy could become continuous, but the photon itself isn't precisely defined.

So, in the end, it's all about which lens you're Ismail Abbas looking through. Both theories have their quirks, and they don't always agree. Welcome to the wonderful world of physics, where the deeper you Ismail Abbas go, the weirder it gets!

@Şükrü Aktaş ...Thanks for your reply

Velocity is defined as displacement over time. There are various expressions of this like dx/dt from calculus. If it is one-dimensional then you don't need root-of-sum-of-squares position (RSS of x, y & z positions) to determine displacement, it is simply X2 - X1, or the difference between final position (2) with respect to initial position (1). So you need some coordinate system for your dynamics problem. 1st rule of dynamics, always define your coordinate system. 2nd rule, develop a Free Body Diagram (FBD) of the object (or entity) in question as it resides within your coordinate system. The FBD must identify ALL externally applied forces acting upon the object/entity. Then you apply Newton's second law to the FBD, F=mA, where F is the summation of applied forces, m is mass and A is resultant acceleration. F and A are vector quantities, m is scalar mass (magnitude only, no direction). Choice of coordinate systems can simplify or overly-complicate the resulting equations. If you define the coordinate origin to be the initial position, it may simplify your governing equation. All of these considerations should be applied before any application of complex modeling tools such as ANSYS, in order to estimate an expected result and recognize unexpected results that need further explanation. Conceptual modeling must come before numeric, to avoid the risk of the common "garbage-in-garbage-out" scenario. The plate speed shouldn't exceed the particle speed of the wave, otherwise your model probably has violation of the laws of conservation in one form or another. Further, if your plate is 'unrestrained' or 'unconstrained', it will give you one answer, but if you try to extract work from it by making it push on a piston or or some other form of mechanical energy conversion for power extraction/generation, that restraint or constraint or impedance will reduce the resultant deflection of the plate. The force acting on the plate over the deflected distance form the product of work (W = F times D all in the same parallel or linear direction or degree of freedom). This product gives a theoretical maximum of the possible energy that may be extracted. Your actuator (piston or generator, whatever it is) will have a conversion efficiency less than unity (<100%) which must be applied in your considerations of power generating capacity. Power is work per time or dW/dt. Be mindful of dimensional units to check for dimensional correctness of any governing equations you derive while assessing the FBD, otherwise you will fall into the "garbage-in-..." trap.

Hello Bikiran Kalita ,

The problem is that your mesh and the dynamic mesh method you used are not consistent. It is complicated to explain what you should do for this structured mesh. So I suggest that you change the grid to an unstructured one and use the Smoothing+Remeshing method.

In a wave energy generation system that uses a cylinder to capture the movement of waves, the amount of air whose pressure is contained can be calculated using principles of fluid mechanics. The key factors to consider in this calculation include the dimensions of the cylinder and the characteristics of the waves. Here's a general approach to calculate the amount of air pressure contained:

It's important to note that the calculation can be quite complex and may require a detailed understanding of the specific wave energy system, the dynamics of the waves in the location of interest, and the mechanical aspects of the air compression system within the cylinder. Real-world wave energy systems often involve additional complexities, such as control systems and varying sea conditions.

To perform a precise calculation for a specific wave energy system, it's advisable to consult with experts in the field who have experience with the system's design and operation. They can provide detailed insights and may have access to simulation tools or models that can assist in making accurate predictions.

One of the easiest ways to obtain data on winds and waves along the coasts of Crete is by using online sources and applications. Here are a few recommendations:

1. Windfinder (www.windfinder.com): Windfinder provides real-time wind and weather information, including wind speeds and directions, for various locations worldwide. You can search for specific spots along the coast of Crete to get accurate wind data.

2. Magicseaweed (magicseaweed.com): Although primarily focused on surfing conditions, Magicseaweed also provides wave height and direction information for coastal areas. It can be useful for obtaining wave data along the coasts of Crete.

3. National Oceanic and Atmospheric Administration (NOAA) (www.noaa.gov): NOAA offers a wide range of weather-related data, including wind speeds and directions, wave heights, and directions. You can access their website or use their mobile app to get detailed information about coastal conditions in Crete.

4. Windy (www.windy.com): Windy is a popular weather forecasting platform that provides detailed wind information, including speed and direction, as well as wave heights and directions. It offers an interactive map with customizable layers to visualize the data effectively.

5. Local meteorological stations: Check if there are any local meteorological stations or observatories in Crete that provide public access to their weather data. These stations often have instruments installed near the coast to measure winds and waves accurately.

Remember that while online sources can provide valuable real-time or forecasted data, it's always advisable to cross-reference multiple sources for more accurate information on winds and waves along the coasts of Crete.

Howdy Selim Molla ,

No.

The problem of fluid behavior after energy extraction in the range of sea states the ocean can accomplish is too difficult to explain mathematically as one's primary activity, and certainly it must not be attempted "on the side" of energy extraction equipment research and development. The situation is not quite that bad in practice, however, especially with your focus on energy extraction equipment.

An engineering approximation to mathematical treatment of oceanic waves after wave energy extraction might be possible with sufficient attention to the energy extracted and the wave recovery under wind stress, fetch, etc. An expression starting from the wave energy equation before interference by extraction equipment which is then reduced by the actual value of the energy extracted would be a start. Then, if you were to factor in the efficiency as an additional loss of energy by the wave and you would have an estimate of the wave energy several wavelengths beyond your equipment, that is, beyond initial turbulence details, etc. For the wave state further along one would have to apply the approximations available for the affect of wind fetch, currents, etc., but that is your field, I'm just a visitor who hates to see questions without replies.

Perhaps this suggestion is too obvious, too simple to be of value, but unfortunately, the explanation you request is not available at present.

Happy Trails, Len

Dear Leonard, ( Leonard Hall )

Thank you your response. Your reply confirms that we think alike. There is no denying what I have written in my comment.

You wrote:

'I think that the gravitational field associated with photon energy is transported with the photon but this is not gravitational attraction which I associate with the effect of a graviton. '- OK. (The graviton ('virtual photon' in has a has adhesive effect in elementary level [imagine it as a microgravity space]

'How does a graviton "create" a photon?'

The problem you have raised is really is under formulation In a 'natural' dochtrine of graviton. It was present in project of Graviton, but the ResearchGate deleted the the project likes links after 31.03.2023

I don't have time to present again, now but I'll get back to it....

But imagine the next analogy: 'Higgs boson' [I do not accept its existence] and its field when is created creates an negative energy concentration which is which leads to a positive energy concentration and after dispaers this energy concentration, same time of a another positive concentration shated out in form of photon when the Higgs field is is ceased.

It works like an arrow. It resembles an explosive volcanic eruption.

So you can imagine what I mean.

And you see, we are facing a very simple natural approach.

We get a very simple natural narrative with this kind of approach to the graviton.!

Regards,

Laszlo

Numerical dissipation and dispersion, as you say, mainly happens for two reasons: (i) insuffiecient number of cells per wave height/length (ii) inappropriate turbulence model.

I do not have any experience with ICFD within LS-DYNA but you should definitely test the results with more cells in the free surface area. Check the courant number not to exceed at least 0.3 in the FS area. Regarding turbulence models, the best but not ideal "out of the box" model for wave propagation is realizable k-E. If you wish that your simulations are long, then you will need different, more stabile turb. model.

All the best and good luck,

Ivan

The center of rotation can be changed by modifying the value of the "rotation_center" variable in the UDF. This variable is typically set to the initial position of the center of rotation and can be modified during the simulation by updating its value in the UDF.

1- Define the new center of rotation as a variable in the UDF:

#include "udf.h"

DEFINE_CG_MOTION(sdof_motion, dt, vel, omega, time, dtime)

{

/* Declare variables */

real x_new; /* New center of rotation */

/* ... */

2- Update the "rotation_center" variable with the new value during the simulation:

/* Update the center of rotation */

x_new = 0.5; /* Set the new center of rotation */

NV_S(rotation_center, =, x_new); /* Update the rotation_center variable */

/* ... */

3-Re-compile and re-load the UDF

Dear Dr. Bulcsu Szekely!

Thank you for your attention to my question and opinion about energy dissipation. I completely agree with you that conservation of energy is the most fundamental law of our existence. I wish you success in your researches.

Regards

Mikhail

Mahyar Radak

These links might be helpful, have a look;

1. https://www.mathworks.com/videos/introduction-to-matlab-with-image-processing-toolbox-90409.html

2. https://www.mathworks.com/matlabcentral/answers/169745-how-to-generate-a-digital-hologram

Hello,

I also found this that might help you: https://www.boatdesign.net/threads/ansys-aqwa-spar-buoy.55934/

It looks similar to what you are trying to do.

You can follow the approach of Chao et al (2014): plot the diversity curves for q=0,1,2 and use the Confident Intervals to tell you whether the differences are significant or not. I think it is the most straightforward method. Hope it helps.

Chao, A., Gotelli, N.J., Hsieh, T.C., Sander, E.L., Ma, K.H., Colwell, R.K. & Ellison, A.M. (2014) Rarefaction and extrapolation with Hill numbers: a framework for sampling and estimation in species diversity studies. Ecological Monographs, 84, 45-67.

You need to use a User Defined Function (UDF) to modify wave profile in channel flow

Hi Vipul Rai ,

since two solid bodies cannot occupy the same volume of space, the parts of the two sources ("at the same location") have to be somehow interleaved, in case 1. However, the spatial extent of these details has to be much smaller than a wavelength.

2nd case: In the absence of the inner shell, the wave generated by the outer shell would carry energy. Together with the wave of the inner shell, both waves add up to zero; if I understand correctly, that's exactly the case of your question.

The energy of the wave of the inner source ends up at the outer source. The energy of the wave of the outer source never leaves the source. So, the outer source is turned into a sink.

The wave may have zero net linear momentum, but it has angular momentum, and this is also reduced when the wave does work on the surfer, which it does not only in starting the surfer moving, when the surfer gains linear momentum, but also in maintaining his/her height in the same position on the wave. The force on the underside of the surfboard (about 1000 Newtons) is equal to the rate of change of momentum in the water.

There must be an equivalent transfer of momentum between the wave and the bulk water.

I expect that while this is happening the circular motion of the wave and zero linear momentum are disturbed for a while.

On the opposite side, waves are generated by transfer of linear momentum and energy from, for example a speedboat. The linear momentum must then be transferred into the bulk water, which exerts a reverse force resulting in the circular motion of the water at the surface and change from linear momentum of the boat to circular momentum in the wave. The rate of change of momentum is equal to the retarding force on the boat, which is considerable before it reaches planing speed.

When the wave hits shallow water the backward part of the circular momentum (at the bottom of the wave) is transferred to the earth, leaving forward momentum which we see in the waves washing up the beach.

Most probably degenerate parametric amplification circuits are what you are looking for.

Unfortunally for you, USA and Soviet applications are secreted, and control of energy produced by these as well.

Reducing heat-wave risk through active and passive measures

by Dan Sandink

Impacts of heat waves and corresponding measures: A review

DOI: 10.1016/j.jclepro.2014.12.078

yes, you can do that also using eave models, like Delft 3d

From the theoretical side, you may need to refer to Marine Hydrodynamics by J.N. Newman, Sea loads on ship and offshore structures by O.M. Faltinsen for details on the explanation of hydrodynamic coefficient. The calculation of IRF can be found in many papers.

If you are asking how to use Nemoh or WAMIT to model a WEC system, the answer is they cannot be directly applied for WEC simulation. You must establish your hydrodynamic model in these code, and build up you own WEC model in other place.

The WAMIT manual has very rich explanantions on both theoretical introduction and how to use it. Also, there are plenty of examples. I would disagree with you that the manual is not clear. I would suggest you to take some time to read the manual.

We know light as a wave but when it interacts with matter, it exhibits particle properties (Photoelectric effect and Compton scattering) and we know electrons as particles but they exhibit the wave properties of interference and diffraction. They are carriers of momentum and energy and have both particle and wave characteristics!

You must know that, macroscopic objects such as electrons, display wave behavior but the corresponding wavelengths are too small to detect. At the microscopic level, the waves associated with material particles are of the same size or exceed the size of the system, so, microscopic particles exhibit clearly discernible wave-like aspects. The general rule is: whenever the de Broglie wavelength of an object is in the range of or exceeds its size, the wave nature of the object is detectable but if its de Broglie wavelength is much too small compared to its size, the wave behavior of this object is undetectable.

In classical physics, particles and waves are mutually exclusive and they exhibit different behaviors but Photons, electrons, and any other microscopic particles behave unlike classical particles and unlike classical waves. The theory of quantum mechanics can simultaneously make statements about the particle behavior and the wave behavior of microscopic systems. The true reality of a quantum system is that it is neither a pure particle nor a pure wave. Depending on the type of equipment used to detect, particles have the capacity to display either “particle” or "wave" features. For example, based on the double-slit experiment (that's amazing and you must read more about it), if we wanted to look at the particle aspect of the electron, we would need only to block one slit or leave both slits open but used an observational tool, but if we were interested only in its wave features, we would have to leave both slits open and don't used observational tools. This means that both the “particle” and “wave” features are embedded into the electron (all of the materials), and by modifying the detect tools, we can suppress one aspect of the electron (As a fundamental particle of the whole universe) and keep the other. When we subject an electron to Compton scattering, we observe only its particle aspects, but when we involve it in a diffraction experiment (double-slit experiment), we observe its wave behavior only. So if we measure the particle properties of a quantum system, this will destroy its wave properties and vice versa. Any measurement gives either one property or the other, but never both at once. We can get either the wave property or the particle but not both of them together!!!!

Indeed Dear Ait Mansour El Houssain

v = 1/ sqrt (epsilon_0 mu_0 ) with these 2 (permitivity & permitivity)values being the physical properties of the vacuum, but there is not a set of equations where these 2 constants are not given, your capture WaveFunction.png shows then inside of the couple field equations.

For an electromagnetic wave in vacuum, group velocity is equal to phase velocity, but in other media rather than vacuum, light speed is not universal & in addition electric fields exists in metalic surfaces, inside metals E_ins is zero.

Dear Abdulwahid Ghazi Mohammed thank you for your answer. If you know any related research, can you please give me more information?

www.digitalwavepublishing.com › pdfs

Well, I had to answer this question myself.

For those interested, see my technical note just posted:

Thank you for initiating this discussion, Amirhossein.

I believe the ability to utilize the generated energy by renewable sources would be more important than the renewable energy technology itself (whether it is solar, wind, wave...). Therefore, I think energy storage technology is the key in the field of renewable energy.

You can find my reports on sizing energy storage systems for increasing the penetration of renewable energy systems using these three links:

1- https://www.researchgate.net/profile/Sm_Sajed_Sadati/publication/327234875_Assessment_of_Renewable_Energy_Based_Micro-Grids_for_Small_Communities/links/5b82ed5d92851c1e1233c6df/Assessment-of-Renewable-Energy-Based-Micro-Grids-for-Small-Communities.pdf

2- https://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=2500877

3- http://solarenergyengineering.asmedigitalcollection.asme.org/article.aspx?articleid=2664169&resultClick=1

1. Oscillating Water Column (OWC)

2. Hinged Contour Device

3. Floating Device

4. Hydraulic Device

There is now a wave energy converter (WEC) design which can create surf offshore. Outer Continental Shelves in water depths greater than 30 meters are ideal for this WEC. Waves 0.3m high can be concentrated to waves over 1.0m high using a variable-depth platform. Autonomous platform depth control is critical for safety and performance reasons. A robust neural network will be required to safely control this quantum increase in kinetic energy input to WEC power takeoff systems

Yes..feel more at ease.

How can we measure "feeling". How can we see "thoughts". Why is a life so important? Why are people like Me and You spending our life to save a "life". What happens after I die? Why does it matter?

History is full of people/emperors/kingdoms who vanished and were destroyed. Who once ruled and killed and looted. And today no one remembers them. Many hate them. Does emotions matter?

Because of one word : me, I, my...

When I think I'm right, and I know more..

Thats when I can never think outside the box. I can never think critically, although I may think that I Do quite a bit of critical thinking.

I can never travel the world.. and learn other's languages. And see how different they live. Yet, better than I ever did. And how much knowledge I've missed!!. .so many effective herbs as medicines I've never heard of. Without any side effects! And I have alot more to learn. ..if I will.

As william james remarked - ''experience includes both particulars and relations between those particulars''. Thus for he sense data requires a means to mutate the mind. If then in the case of scale invariances a form of universal archetypes can arrive to human consciousness in all but name, a tabla rasa representation, contents of which are 'solitonically' paradoxical in infinite fields of potential interpretation when it comes to the phenomenology of the mind. I.E - crossing a short bridge from invariance to self similarity, which can be unbound from that similarity. If so we certainly can ask if this shall be the way by which 'the self' can define that self in the way you infer ( which appears to be evolutionary and of an emotional intelligence quality ? ). - indeed whether scale invariance in the neuroscience can interface in these ways.

Your model seems very like one i have worked on for many years. Perhaps mine has self organised criticality where yours has an event horizon. They both propose that the physical brain is not conscious, that 'consciousness' is quantum - that the brain is chemically sampling explicit sense data, using a cross-over process between sampling and awareness, converting chemical results over quanta, and passing those solitons on to be processed in the subconscious leading to a boundary condition field of the self - natural selections differentiation.

Solitons might even be in competition when we consider paradigms like ( just say ) - cognitive dissonance requiring the conscious overrides which lead to and define a persons evolution and so on. However - this research in whatever form has the potential you suggest it has imho

While there exist many procedures for automated arrival time picking of seismic phases, assessment of timing uncertainty and identification of such phases remains a tricky business. We routinely apply a semi-automated procedure that is tuned to a hand-picked and carefully evaluated data set. If you are interested in such procedure please check the following publications (they are available through my page on researchgate):

Diehl et al. 2009, GJI; Diehl et al. 2011, NMSOP; Kianimehr et al. 2018, JSeismol; Rezaeifar&Kissling 2018, GJI.

regards,

Edi Kissling

Thank you Mohammad, the main purpose of the variable-depth platform is to create surging waves and two-body harmonic motion. The heave/lift motion is a small fraction of the potential power takeoff, ~5-10%.

Chris, a bit of friendly advice. You talk about WEC, but no where in your post do you mention what it stands for! Avoid acronyms.

WEC: Word Endurance Championships, World Energy Council, White Edge Crack, Washington Electric COOP, and the list goes on

There is an overview of the wave energy conversion industry in the background section of my blog:

The first patent application pertaining to my wave energy conversion work was filed in March 2007

One of the biggest problems is fatigue. Every spot on the ocean averages 6 million cycles of wave loading in a year so anything you put out there is by default a fatigue test machine. It's not a question of if it will fail, but how soon and in what ways so the cost of repair and replacement has to be figured into the operating costs. There are also issues with NIMBY and with getting the local power companies to allow you to connect to their grid. There has been an enormous amount of work done since the 1970's on a huge variety of schemes, a lot of which never had a chance of lasting more than a few weeks or until the first winter storm came in. The amount of wave energy available is actually increasing a few percent a year off shore, but since much to that is in the longer period ranges greater than about 10 seconds, most of it is not reaching the shallows as it is eaten up by bottom friction as it comes up the slope.

Interested

I think (adaptive) bistable power capture mechanism is one of the promising technologies for wave energy utilization. We have done some numerical work on this nonlinear mechanism (a paper on this has been accepted by Applied Energy) and find that this adaptive bistable mechanism with suitable parameters can significantly broaden the frequency bandwidth of a point absorber WEC. More details can refer to the attached paper.

well, you can make use of the waves energy generated via the river water to apply stress on a piezoelectric beam which is then you need to rectify it and store it in capacitors.

Please feel free to have a look at the piezoelectric energy harvesting techniques as below:

Dear Mr.James Garry

It is just a personal interest,my major study is in a different field.

The sources of gravity are quantized. So gravity is quantized. Theories don't seem to capture the physical reality. From Feynman the graviton is postulated to have a quadrupole moment but no dipole moment.

For a long time it was thought that a graviton could be produced by combining two electromagnetic dipoles. More recently the dipoles have been demonstrated with their interference pattern to be producing a curl free vector potential of kinetic energy which passes through shields and barriers and is detected in a Josephson Junction.

Gravity field is usually represented as potential energy. Moving of a Graviton implies kinetic energy which occurs in this question. Theories don't reconcile the difference. Maybe the Graviton does exist as a field component of localized stress energy like a set of quantum states which satisfy the requirement of potential energy.

Definitely a good idea, Michael; I was hoping that I could get away with using a single line laser, so I wouldn't have to invest in multiple lasers.  And yeah, if I could find an accurate simulator that I could pull data from, I would definitely love that approach (would save a lot of time and labor)

The cause of large amplitude of basin transduced surface waves are

1. Transmission coefficient at the basin-edge is much larger than what we expect in case of body waves.

2. Sudden drop in impedance in basin causes the amplitude amplification

3. Further, the amplitude amplification due to decrease of wavelength in basin is much larger in case of surface waves since amplitude decrease with depth is exponential in nature.

Use this forum it can help you. Good luck

Dear Fedor,

Thank you very much for your interest and suggestion. I hope to share the results as soon as possible.

to reconsider is that measuring/observation influences the particles as well as estimating probability: by squaring the wave amplitude; for we could consider the inverse, i.e. the square root to realize that a particle cannot be located in two different places simultaneously (square root assigns to one value: two values: +/-).

It looks like a mistake to me.  It could be said that most of the energy was contained within the band up to 1 kHz.  That is likely to be true, looking at the time signal, which doesn't have much in the way of higher frequency components.  The 500 line does have the most energy, but because the vertical axis is amplitude, it doesn't have even half the total energy (it doesn't have most of the energy!).  If you assume energy is proportional to amplitude squared, the nearest four lines have more energy in total that the tallest line.

Krishneel, how are you measuring your 4%? How do you measure the input power? If it's the total input power to your wave making machine in your tank (I have to assume some arrangement like this) then I don't think 4% is at all bad . . . Any other comments?

@ Max

Yes waves are gauge forces and act by pushing things away, in different patterns of action.

Dark energy pretty much follows the pattern of E-M energy, but is orders of magnitude smaller than E-M waves like Hawking said.

But given the vastness of the Universe that amounts to an awful lot of energy-approx 73% of the energy of the Universe.

Thank you very much. The mentioned pdf file seems to be very useful.

Dear Reza,

pl download following link which may support your resesrch work.

All the best

 U.S. NDBC/NOAA maintains a wonderful data site of wind-wave buoys around the world, but mainly U.S. coasts. You can go to the web site:

to select a buoy then go to the current or historical data to download wave energy spectrum. The wave action is defined as E/c (E energy, which is proportional to wave variance, therefore the spectral density, c is phase speed related by the frequency by the dispersion relationship). Once you have the energy spectrum, you can compute the action spectrum by A(f)=E(f)/c(f) -- spectral component by component.

Why you do not try a simpler problem to better understand the physics. I suggest that you use the approach of the paper DOI: 10.1016/j.energy.2012.07.042 . After you have these results you can start by improving you solution. Beware not have an incidence angle above stall! In this condition, the Wells turbine has a very low torque. 

Depending on the layout of panel, you may get quasi-isotropic laminates that are actually isotropic in terms of velocity for certain wave modes.

Considering countermeasures in response to tsunamis is definitely outside my field of expertise; however ideas generated from those outside the normal realm of thinking can sometimes turn into feasible solutions. Approaches to tsunamis should no longer be reactionary; after all of the death and destruction caused by tsunamis, they should be planned events.

It is my understanding that tsunamis are generated by earthquakes, volcanic eruptions, underwater and above water landslides, and anything else (man-made or natural) that can disrupt the flow of ocean waves in a massive way. Seems to me with all of the advances in technology that as soon as one of these catalyst events occur, it is inevitable that tsunamis will develop. These events keep happening in the same region, to me it is feasible to plan countermeasures ahead of time.

My theory posits that multiple sonic boom generators (containing analytic components) can be installed on ocean floors in regions predisposed to tsunamis. Tsunamis can travel at 500 mph and can be 100 miles in breadth, and can reach 30 ft. in height. Efforts to neutralize waves must be immediate to have any chance of impacting strength of waves. One sonic boom generator does not seem feasible to me, one generator would only have a potential impact on a minuscule part of a tsunami. Tsunamis are massive, they require massive countermeasure efforts.

These generators can generate sonic waves in ascending manner that build up in intensity in increments. The worst thing to do is to set off huge sonic booms that can actually create worse problems than the original tsunami. Overkill can create a reverse tsunami that can travel back to area of origin and add to destruction already experienced from catalyst event. These sonic boom generators (if they can be developed) could be placed close to known catalyst locations (ex. starting next to active volcanoes, close to known earthquake epicenters, etc.) and be placed in intervals all the way to vulnerable coasts. My idea is to be aggressive from the start, but not so aggressive that efforts create worse problems. Sonic boom generators that are located the farthest from the coast can send out sonic waves to chip away at the tsunami as it travels. As a tsunami travels, the properties of the wave would have to be analyzed to determine whether efforts have indeed decreased the potential impact on destined coast. If at a particular point, the tsunami has not decreased enough in intensity, further sonic wave efforts would continue. I can appreciate that my thinking can be viewed as rudimentary, please remember that I am a complete novice and the laws of physics and engineering capabilities do not limit possibilities in my thinking. 

Good papers\theses for studying:

Michailides C, Loukogeorgaki E, Angelides DC. Influence of Connectors’ Stiffness on the Performance of Flexible Floating Breakwaters. 19th Int Offshore and Polar Eng Conf, Osaka, Japan, ISOPE, 2009;3:1094-1101

FLOATING BREAKWATER PERFORMANCE - WAVE TRANSMISSION AND REFLECTION, ENERGY DISSIPATION, MOTIONS AND RESTRAINING FORCES, RON COX (1) & DANIEL BEACH, 2006, Proceedings of the First International Conference on the Application of Physical Modelling to Port and Coastal Protection

Numerical Analysis of Wave Transmission behind Floating Breakwaters, Sutrisno Sutrisno, Norwegian University of Science and Technology, Sutrisno 4192192 (DIVA)

Experiments on wave transmission coefficients of floating breakwaters, G.H. Donga,, Y.N. Zhengb, Y.C. Lia, B. Tenga, C.T. Guanc, D.F. Linc, Ocean Engineering 35 (2008) 931–938

Wave basin experiments on floating breakwaters with different layouts, Luca Martinelli a,, Piero Ruol b, Barbara Zanuttigh, Applied Ocean Research 30 (2008) 199207

McCartney ΒL. Floating Breakwater Design. J Waterway, Port, Coastal and Ocean Eng 1985;111(2):304-317.

Oliver JG, Aristaghes P, Cederwall K, Davidson D, De Graaf F, Thackery M, Torum A. Floating Breakwaters-A practical guide for design and construction. PIANC; 1994, Rep. 13.

Isaacson M. Wave Effects on Floating Breakwaters. Proceedings of the 1993 Canadian Coastal Conference, Vancouver, Canada 1993;1(2):53-66.

Performance of twin-pontoon floating breakwaters, Bhat, PhD Thesis, University of British Columbia.

Dear Morteza,

As you know, Phil Pauley is the designer of such state-of-the-art power plant (a hybrid of solar and wave energy generator). So, you may find some useful information in this regard from the following website. 

Good luck,

Morteza Shabanzadeh

You got me thinking.... this link may help explain it: http://www.es.flinders.edu.au/~mattom/ShelfCoast/notes/chapter05.html

The short answer (at least in terms of the  hand-waving explanation in my head) is that nothing is moving at anywhere near the speed of sound (if it did, we WOULD hear it). Bernoulli recognized the gravitational forcing for tides in 1740 (the "equilibrium tide" model). The driving force (provided by sun and moon) does travel around the planet at orbital speed, but the water simply can't move that fast. Laplace developed the "dynamic theory of tides"  in 1775 to try to take this into account.

If a particular point in the ocean is experiencing the force that creates high tide, the surrounding water flows towards that point at a modest speed of at most a few km/hr (and in the opposite direction if it's a "low tide force"). Unlike a wind wave (which will continue to propagate after the wind stops), tides are best thought of as a "hump" that exists while the "gravitational' forces (in quotes because with centripetal acceleration etc., its a bit more complicated than that - see http://faculty.washington.edu/luanne/pages/ocean420/notes/tidedynamics.pdf )  are present.

Open oceans get two tides a day because the forces that produce them peak twice a day at any given location. When you throw in a real planet - with continents, varying depth and spin - you will end up with a complicated picture with nodes, antinodes, resonance in some areas and "propagation tracks" that do not follow the moon's path (Coriolis effect).

The first link has some information re resonance .....

Let me know if my hand-waving helped, and fell free to correct any errors......

Hi

Conversion is simple,but the total efficiency is " very low " because piesoelectric

converter (sensor) can not convert the mechanical energy in any form to electric

power in acceptable level.

Please before starting your project study in detail about conversion efficiency in any

"types and arrangement" of piesoelectric devices.

Best.....

A/H (Design Engineer)

Sure. Here's 20 minutes of wave data I collected in the Muskeget Channel, Massachusetts a couple years ago. Have fun :)

These buoys record Dominant wave period (DPD) which is the period with the maximum wave energy.  If there was a 'classic' unidirectional spectrum then this would be equivalent to spectral peak period.  It is linked to MWD which is the direction that the waves with the dominant period are coming from.  If you go here http://www.ndbc.noaa.gov/  and find your buoy(s) you can check the output descriptions

For all Owen Clarke Design projects, the common denominator is performance, regardless of whether the yacht is a cruising or racing design. Our designs always prove to be fast. This is partly due to the tools that we have available to us, the way in which we use them and our partnerships with some of the world’s leading engineers, designers and marine technology consultants.

As professional engineers and designers we offer our skills, experience and use of the tools at our disposal to individuals, yacht designers, boat-builders and other agencies as well as applying their use to our own designs. OCD have recruited qualified naval architects in recent years in order to expand this area of our business. We have continued to invest time and resources in the application of analytical methods such as Computational Fluid Dynamics (CFD) and Finite element analysis (FE) to fluid and structural engineering problems, expanding the use of these tools through our range of designs as the software and services have become more cost effective.

The starting point of any new design is to develop a set of hull lines which define the geometry of the boat. We’ve been using Maxsurf, the world’s leading yacht design software since drawing the lines of our first racing boat, the 35’ trimaran Fiery Cross, in 1987. Since then the product has also been developed for use in the design of commercial craft and ships. It remains however the most utilised yacht design software for designers the world over.

Please try to see relevant papers by Dr. Ir. Johan Weichers. He is one of the pioneers in this field. You can also see some works by Prof. Grant Hearn. These works are all done in late 80s and early 90s.

This type of wave energy converters have a intrinsic problem: the amount of torque they need to withstand!

This results from the coupling of the wave slow motion (periods between 8 to 12 s meaning angular frequencies between 2π/12 ≈ 0.5 and 2π/8 ≈ 0.8 rad/s) with the electrical generator, typically ∼ 500 times greater. 

Considering a rated power of P = 250 kW, the order of magnitude of the force is

F = P / v = 10^5 N,

since the wave velocities are around v = 1 m/s. It is obvious that the costs associated with a structure capable of withstanding this level of force, with a cyclic behaviour (fatigue loads), should be very expensive.

The main question about wave energy remains to be answered: can a WEC be designed to withstand the loads and produce energy at a when competitive price compared with offshore wind? The assessment of the commercial prospects for wave energy is difficult, but clearly the path to go is to decrease the system costs and increase the reliability. To do so, the WEC designers should increase of the rotational/linear speed to decrease the torque/forces involved in the PTO system.

Open to correction. hope this is of some use...I think you are looking for a physical explanation..Consider

the voltage wave as a packet of positive charges traveling along the conductor.

When this packet encounters the ground (short) a good amount of electrons

are drawn up from the earth to neutralize this instantaneously (that is zero voltage).

This would I suppose be akin to the concept of p holes traveling in semiconductors

and we imagine a negative wave mathematically to simulate this effect.

Two references which accord with the above recommendations i.e. NL Froude Krylov forces and linear radiation (and include one of the respondents as author) are:

Merigaud, A., Gilloteaux, J.-C. and Ringwood, J.V. A nonlinear extension for linear boundary element methods in wave energy device modelling, Proc. OMAE 2012, Brazil, June 2012

Gilloteaux, J.-C., 2007. “Simulation de mouvements de

grande amplitude. application `a la r´ecup´eration de l’´energie

des vagues.”. PhD thesis, Ecole Centrale de Nantes

Hope that is some help.

Interested and planning to start research career in it. What can we discuss?

Then is not a waveguide but a kind of (pseudo) TEM line...

The scatterring produced by gases and aerosols in the atmosphere are very important for remote sensing techniques in the visible and near infrared regions. Aerosol particles visible in satellite imagery can also be used to study dust storms, wildfire smoke, volcanic ash and urban pollution dispersion. Aerosols also influence the earth radiative heat budget and are one uncertainty in studies prediction global climate change. That´s is a very short answer to your question. The are several books about atmospheric aerosols. Ex: http://www.amazon.com/dp/3540262636/ref=rdr_ext_tmb

In 7 OCT 2013, Dr. Zong-Hong Lin et al., published paper....

Water-Solid Surface Contact Electrification and its Use for Harvesting Liquid Wave Energy

in this work: A newly designed triboelectric nanogenerator is based on the contact electrification between a patterned polydimethylsiloxane pyramid array and water. Cost-effective and simple, the prototype triboelectric nanogenerator shows the potential to harvest energy from liquid waves and serve as chemical and temperature sensors.