What speed is your turbine rated for? If 25000 is beyond the rated speed it could well blow apart due to centrifugal stress..

Thanks for your reply. The turbine has not been rated as I am the inventor and I have no expertise in this area. I have a product now that can spin faster than most jet turbines. Even the bearings used to support do not get very hot as it spins at these high speeds. It is completely different than any other turbine ever made. It is made out of aluminum at present and I am thinking of making it out of stainless 316 for virtually any use. If you go to pentapowerturbines.com you can get a glimps of it as I just had the site started. I've been told by a few engineers that it has done better than the Betz Law says that is possible. No(or very little) air escapes the turbine if directed in at the correct angle. It is only held together with set screws at present and does not seem to have any stress showing. The other thing that I will need, will be two variable input alternators to gather the power that is being create. Any suggestions? Thanks. Pentapower.

Thanks for your reply. I was lucky enough to get the design and still am trying to figure it out myself. The last physics and math I took was about 25 years ago and I rarely had to use it inbetween. Just minor stuff in everyday life, you know. So doing all the mathematical is a little beyond me. The photos you saw on the site didn't give the turbine justice. Everyone who has seen it in opperation cannot believe the way it works. With almost all the energy taken out of the air directed at it, I've been told, by some who did not see it opperate, that there couldn't be any power generated as power cannot be generated without movement. The ones who have seen it cannot figure it out. That is why I need to get the proper specs. Your help is greatly appreciated. Thanks. PentaPower.

I've been told by a few engineers that it has done better than the Betz Law says that is possible.

Don't trust those engineers. Without torque figures, they cannot have any idea how efficient your device is. You've said that you have not been able to get torque figures, and without those no respectable engineer would make any efficiency claim or estimate. I hope you didn't pay these "engineers."

Any suggestions?

If I were really strapped for funds, the last thing I would do is make another one of these out of stainless steel. If you have one that works, then simply hook it to an alternator -- using one or two makes no difference, so use one. Then you have everything you need to measure output. Belt or chain drive losses are of almost no consequence, and can be calculated out of the results in any case.

Driving an electric generator is a classic dynamometer method. You seem to be avoiding the simple and obvious means for testing your device? Why?

Thanks for your reply. I'm not the most mechanical person, I was just fortunate to have the idea. Plus I work three jobs just to survive and don't have very much time to spend in trying to do these calculations. That is why I have to get a little assistance. The machinist, who I've got to mass produce these turbines, as well as the Honda Racing Team, think that it does have potential. I'm not the one to perfect the turbine, but from what I have done might change the thought patterns of others and maybe we can overcome these little setbacks. Afterall we humans can do wonderous things. Thanks. PentaPower.

Apart from referring to manufacturers' published information, some measuring equipment will be needed.

Thanks for your reply. I am the inventor and I do not have anything to look up except from others who have knowledge in this area. Everyone who is wanting my turbines is asking for specs and I am not the one to ask. I need some way of getting these results and I don't know where to look. Any ideas? Thanks. PentaPower.

Or do I even have to worry about the torque if I can get this kind of movement using closed bearings as the support?

Absolutely you have to worry about it. When you connect some sort of generator (alternator in your case) to the spinning turbine the alternator moving mass will slow the turbine. When you draw power out of the alternator the alternator will appose the movement of the turbine slowing it further (motor/ magnetic theory). The more power drawn, the higher the load on the turbine. If this load exceeds the produced torque of the turbine the turbine will stop. It is no use having a really fast turbine which produces little torque.

http://www.google.co.nz/search?hl=en&num=100&q=motor+torque+testing+procedure&meta=

http://www.scienceprog.com/easy-way-to-measure-motor-torque/

etc.

In the end your turbine will be running a lot slower than 25,000 RPM, and to get useful power out of the alternator you are going to need some sort of reduction gearing system to both get the right frequency current out of the alternator AND to increase the torque allowing you to get more power out of the alternator.

Thank you for your help. I did as you said and the radius was 12cm and the weight was 1.5kg. Using that formula I got .1764 Nm. Mind you the test was not done with 100% accuracy. There will be an alternator at each end of my turbine and they will be of very low resistance. I probably will not get the turbine going quite that fast as I used about a 60km wind to achieve that RPM count before. Any other suggestions are welcome. Thanks. PentaPower.

It depends on how much electrical experience and knowledge you have, but for a practical test of the turbine design you need to do an electrical load test to see how much power you can generate with your turbine design.

Try connecting the alternator to the turbine and connecting a variable resistance electrical load to the alternator along with an ammeter and voltmeter. Pick a wind speed and vary the electrical load to see how the turbine reacts and how much power you can generate before the turbine stalls. You will also need to experiment to get the right gear ratio to get the alternator operating at the correct speed for the correct output voltage and frequency and producing maximum torque (output power from alternator). Note that altering the wind speed will change the alternator output (among other things), and altering the alternator electrical load will alter the turbine rotational speed (by an amount that will likely surprise you).

You can calculate the results just by using basic mechanical and electrical theory and then plugging in the numbers, but it is more fun and educational doing a practical test (even if it is less accurate), especially if you are new to the wind generation field.

Bear in mind you will still need to learn about mechanical and electrical theory in some depth if you want to successfully complete your design project. I cannot stress this enough.

Jack - Two large multi-turbine, multi-MW wind farm projects commissioned and counting.

Thank you so very much for your help and encouragement. I will do as many tests as I am able and will continue to come and get input like this. I'm sure I will have fun doing the practical tests. I've done a few experiments in the little time that I have had to allocate to this. I need to spend more time as this sort of device is needed now and not next year. I'll continue checking this page when I can as you gave me lots of homework. Thanks again. PentaPower.

I presume you are talking about using two alternators for balance/symmetry. In general, larger machines of similar design are more efficient than smaller ones; a single alternator on one end will be more efficient than two smaller ones.

You indicate that you have a digital tachometer. Is it measuring shaft revolutions per minute, or blades passing per minute? I can not believe that the rotor shown in your photos could withstand 25,000 RPM. 25,000 RPM is 417 Revs per second. The circumference of your 12 cm rotor is 37.7 cm, or 0.0377 m, so a point on the outside of your turbine would be moving 0.0377m*417/s=15.7 m/s. Centripetal acceleration=v²/r=(15.7m/s)²/0.06m=4,120 m/s². The acceleration of gravity is 9.8 m/s², so the outside of your turbine would be experiencing 4,120 m/s²/9.8 m/s²=420g's! That means one ounce of aluminum on the outside rim would be experiencing 420 ounces, or 26.3 pounds of centripetal force.

As others have said, if you are indeed spinning this thing that fast, you (and any spectators) had better stand well away from it, off one end or the other. If you plan on selling this, you had better have some major liability insurance!

I wish you well!

Thanks for your reply. I'm not sure how it does it's work, but it almost lifts off. The turbine doesn't even seem to have any stress, nor do the closed bearings on either end. When the air enters at the perfect angle, it hits one of the inner blades and then begins its travels through the rest(outside then inside...) and the air does not seem to come out. The turbine just seems to go faster and faster. With some kind of alternator with low resistance, this would definately create electricity. I've tried holding the shaft and then turning the air on and yes at low amounts of air it starts slowly but when it starts going faster it just takes off. The bearings that I am using are not the most efficient and are causing a little resistance. I've read a few articles on building alternators and if I were to put permenant magnets on the shaft on both sides and run them through wire coils that are fixed to a shroud of somekind, wouldn't that be a simple way of building one? As is the turbine is turning as one piece just using closed bearings to hold it in a stand. Thanks. PentaPower.

"...) and the air does not seem to come out."

Whatever it may seem, exactly the same amount of air that enters the device MUST exit somewhere. No air is 'used up'! There will of course be transients at startup, where the pressure will change inside the turbine. Once the device is spinning, the 'centrifugal force' will cause air to be expelled, and the pressure inside the turbine will be below atmospheric pressure. In a squirrel-cage fan, one end is open, and the higher atmospheric pressure causes air to enter through that open end. Since your turbine is closed at both ends, the air must enter from the side.

AS others have pointed out, ANY device intended to extract energy from the air passing a moving vehicle will ALWAYS increase the fuel consumption of the vehicle by a greater energy value than the energy generated by the device. There could conceiveably be an exception to this rule in the case of vehicles that have large turbulence (like 18-wheelers), IF in addition to extracting energy, the device also reduced turbulence significantly. But even in such a case, I believe the greater energy saving is from the reduced turbulence. It would be worth your time to investigate the energy saved by placing pointed rear ends on big trucks.

If you want to appear as an intelligent energy saver, get that car off your website PRONTO!

If you really want power generation on a moving vehicle, you are better off saving on the extra weight and just using the alternator installed on the drive engine.....

Your turbine will simply add drag to the vehicle and consume even more energy.

Thanks for your reply. On my site www.pentapowerturbines.com it shows a few amature photos and describes it a bit. It may only weigh a couple of pounds at best without any alternators. You may see that it is cylindrical in shape and all air that is forced into it properly is eaten up which can be transformed back into a different type of energy. Isn't drag a causal of the air being obstructed, n'est-ce-pas? I hope that this helps in your understanding. Once I figure out how to get all its specs, maybe it'll help me and everyone else understand this a little more. Thanks. PentaPower.

Congratulations !!! PentaPower,

You've done an amazing job and going to improve on it. Well done and keep it up.

Now coming to your problem, the basic calculations han be found in electical and mechanical physics or engineering books or even caterlogues on turbines, generators and bearings.

All these formulae are based on the following equations.

Mech. Power = Torque X ω = T X RPM X 2 X Π / 60

Elect. Power = V X I

If the turbine is 89% efficiency, Then the elect. Power = 0.89 X Mech. Power

Torque of a revolving body (T) = Moment of inertia (I) X angular accelleration (α).

I = m X k² where m = mass of rotor in kg and k = radius of gyration in metres.

k can be easily approximated by looking at the cross section of the roter.

Good luck!!

Thank you for your reply. I'm trying to use all different calculations and am getting a few results. I have Compact Tuning Lad(one of Honda's Racing Teams) getting ready to help me. They will use two alternators from their stock to do a bit of testing. Once all the testing is done I will then be able to move forwards. Thanks. PentaPower.

If the turbine is 89% efficiency, Then the elect. Power = 0.89 X Mech. Power

Usually, the terminology is not used in this way. An 89% efficient wind turbine delivers mechanical power equal to 89% of the wind power input. (Of course wind turbines are 89% efficient only in dreams.) Electric power delivered will then depend upon the efficiency of the generator, which can be about 90%, more or less. Then, overall efficiency from wind to electricity would be about 80%. Our current best wind turbines do not come close to this figure.

PentaPower claims to have created a device which destroys mass -- he says wind goes into his device but none comes out. We have had many CR4 visitors who have claimed similar things, declaring the laws of conservation of mass, conservation of energy, thermodynamics, etc to be invalid. A recurring theme is that the inventors are somehow unable to perform even the simplest and obvious tests to substantiate their claims.

Perhaps PentaPower will be the one who does not fit this mold, and will show us that a wind turbine that takes in wind but lets none out is possible. Although that notion strikes me as completely far-fetched, I too, say "good luck with that."

Thanks for your reply. I know that it seems not possible but that is what is making people wonder when the see it in action. I know what is being taught as I have learned a few things through the years, but there is most times room for improvement. I'm not saying that I have done all wonders but would like everyone out there to believe that we can do it with some help. If we all use our minds, we can accomplish pretty well anything. I'm just the inventor and fairly soon the turbine will be out there for everyone to play with. It's a start and I feel that we(mankind) can go further, with it(my turbine) or more advanced versions. It doesn't have to be a rocket scientist who gets these kinds of ideas, it could just be an ordinary 'Joe' like me. Trying to get help(money) from anyone when you are just a nobody is almost impossible. Luckily I had someone see my invention work and believed in it. "United we stand, divided we fall." Thanks. PentaPower.

To test the torque, simply hook the turbine to a dc permanent magnet motor, with appropriate gear reduction (initially, just use a belt). Load the motor (which acts as a generator when driven by a mechanical source) and measure the voltage and amperage. (The load can be almost anything -- headlights, water heater elements, etc. -- just start with low power into the turbine, and work your way up). Once you have the power output (volts x amps) divide by .746 to convert to hp. (From hp you can get torque at the windmill itself using this: rpm x torque / 5252 = hp.)

RPM, alone, is meaningless -- an ordinary Dremel tool can operate at 35,000 rpm, but has very low power.

If the turbine you are spinning fast is the one you are holding in the picture on your website, don't spin it at 25,000 -- if it flies apart, you could hurt yourself or others.

Mounting any turbine, no matter how efficient, to a moving car will cause the car to consume more fuel (or electricity) than the turbine can generate. Thermodynamics... it's the law.

The article on your site says "As the car moves, the passing air would turn the turbine, and Moore says the electricity could be captured and stored in onboard batteries. "(That power) can be sold back to the grid through future battery depots," Moore says.

In an electric vehicle, however, this on-the-fly recharge could potentially increase the driving distance and decrease the need to plug into the grid for a full charge. So far, Moore has not done any real world performance testing of his device.

Best to do the testing first, and then make claims. What leads you to think the device is 75% to 90% efficient if you have not done any testing, and do not even know how much torque is produced? I doubt that your turbine is 75 to 90% efficient -- I'd guess perhaps half that. Savonius style turbines are not very efficienct -- their virtue is in simplicity, and if vertically oriented, omnidirectionality.

But suppose it is 90% efficient. That means that to generate 1 kW with your device mounted to a car, the car would have to supply roughly 1.1 kW extra, thereby using more fuel (or electricity) than the device produces. You'll operate at a net loss, shortening, not lengthening an electric vehicle's range.

If the car is parked and facing into a wind (a wind generated by something other than the cars engine) then your scheme would help charge a battery. However, if you do the math, you'll find that a huge windmill is required to make a meaningful contribution to charging a car. The same is true for solar cells: covering a garage roof works, but covering a car's roof does not (other than to run, for example, a fan to keep the interior from becoming too hot)

There are several other CR4 threads about windmills on cars.

Thanks for your reply. A question to ponder on - When I force the air into my turbine at about 40 mph, and there is no air that escapes out the rear, what is happening to the drag? Or is there drag? I can put the turbine in a lite frame with closed bearings to support and the air forced into it doesn't even push it away on a smoth surface. If I put a regular house fan in front of the forced air, it would be thrown back and fall over. When I made the turbine go 25,000 rpm, it almost seemed to lift off the table a little - straight up. With the design there is no worry of it falling appart. Wouldn't it be nice if putting this kind of device on any moving vehicle would eliminate drag and still create electricity? Betz's Law doesn't recognize this kind of turbine, but it doesn't mean that it cannot exist. I think that some laws might be out-dated as we are always improving upon things. What ever the human mind thinks about, or dreams, is a possibility. We've already proven that. Look how far we've come from the late 1800's. In less than 120 years we have gotten to a point where we can do almost anything we can imagine. Thanks. PentaPower.

Hi,

Aluminum is the best choice for any rotating equipment that stays cool and is operated in non-corrosive gas.

Stress from centrifugal force is going up with density.

So to evaluate materials for fast rotating machinery it is necessary to compare the ratio: strength/density.

This is very bad for stainless steel - so forget about these.

Very good Aluminum alloys (7075 and 7475) have ultimate tensile strength (UTS) of near 700N/mm² and density near 2.7g/cm³. Ratio is 259.

Best available steel is 300-maraging (1.6356) with UTS of 2400N/mm² and density near 8g/cm³. Ratio is 300.

For these critical applications I would only use aircraft-qualified material, so cost will be near 50$/Kg for both in small quantities, but the Al much cheaper if large quantities are asked.

When machining cost is considered the Al is far superior.

Have a look at the creep-strength data - you have to be sure that after prolonged use there is no catastrophic failure!

Turbo-molecular pumps are built with these high-strength Aluminum-alloys!

Look at one at the rotor to shaft attachment - your design needs a big improvement!

Your blade to end-ring attachment will give rise to high stress concentrations, think about deformation of blades by centrifugal force and about deformation of end-rings.

Any abrupt change of cross sections to be avoided, else there will be minimum a stress intensity factor of 4 to 8! You will not want the material to exhibit gross strain there!

Torque testing: modify a disc-brake and measure force (by weight is simplest).

RHABE

Thanks for your reply. I've already received quotes from my machinist and stainless 316(marine grade) is actually cheaper(with them) than aluminum. Plus I can use the stainless in many different applications, from up in factory smoke stacks, to forcing radiator fluid through and cooling while it creates electricity for a fan help cool the engine, to Ion Propulsion of satelites or travel in space. Whatever we imagine we can accomplish. Thanks. PentaPower.

Get some textbooks or look at other engineering results and you will see that "stainless steel" is not a good idea for fast rotating machinery.

(Why are pistons in car's motors from aluminum and only large ones in ship's motors from cast iron?)

Get a first idea about stress in beam bending and you will change your design to much shorter length.

Get an idea about stress intensity factors and you will change the design of the endplates.

RHABE

Rhabe,

I am not so sure why you are saying this. 40000 rpm turbochargers are made of steel. 14000 rpm gas compressors are made of several varieties of stainless steel, 30000 rpm jet engines are made of a variety of steels.

There is no aluminum in any of those.

I am not saying that a good grade aluminum is not appropriate here, but for most turbomachinery applications steel is used, including 316 stainless.

Hi Steve,

you are absolutely right,

as there is any considerable heat (above 100°C) to withstand then there is no Aluminum possible. (I thought about wind turbines seeing the pics from the above mentioned website.)

Turbochargers: one side hot: steel, other side cold: Aluminum. (Cold is still too warm to touch with bare fingers).

Gas compressors: I don't know. Running at centrifugal limit? Which type?

Jet engines: very hot and at the limit of both centrifugal stress and creep. No longer "steel" - this was the start in 1944 with cobalt-steel by Heinkel and Messerschmitt with typical lifetime of 25 hours. Now Co-Ni-Fe-Cr-Al alloys, Chromium and Aluminum oxides generated on the surface to protect from further oxidation. A network of internal bores to pump fuel through - to get some very necessary internal cooling.

RHABE

Could anyone advise me please - is there any software to
evaluate the effectiveness / efficiency of different "windmills"?

Search finds general advice on "this type is better than that type"
but no determination of prototypes. Some sort of cad / drawing
package which says... "no that's worse.. or that's 58% more efficient"
would be ideal - Does anyone know of such please?

jt.

Thanks for your reply. I'm sorry, I'm not the one to ask. Since no one has answered your question I will say that there are many turbines now coming out. Some good and some not so good. I guess the only way to find which is the best is to go over the specs provided for each. That is what I started this thread for was to get the numbers that I need to continue on with my invention. Maybe someone else has a better idea as I am a newcomer to this aswell. Thanks. PentaPower.

if you are looking to run a gen set off of it your best bet is to set up a gear box on the cold end of the turbine (ie the intake end) with the gear box you can run the gen set with less of an impact to the turbine. but remember 80% of your turbine's power will be use by the turbine just to keep it self running.

also 25,000 rpm is nothing i work on bigger one (ie a solar turbine Saturn mark I and II, Centaur 50 and Taurus 60) the smaller your turbine is the easier it is to spin at a higher RPM. i would not use AL for a turbine way to soft for the high temp. and press. for it to take with out it giving way on you

Thanks for your reply. Using gears reduces the efficiency. That is why you say 80% of turbine's power is used to keep it running. Mine has no gears, no belts, no pulleys. That is why I'm quite confident(even without specs) that my turbine is very efficient. Besides even the bearings holding my turbine up did not even get warm when it was at 25,000 rpm's for a few minutes. Does that not show that there was little stress on the turbine? Thanks. PentaPower.

No, sorry that does not prove anything.

I am also trying to figure out who decided that 80% of the power of a turbine is used to keep it turning, that is not right either.

Gears belts pullys are certainly part of system efficiency, but not a large part.

I am quite confident your turbine can do little real work.

I am looking forward to you proving me wrong, but I am not wrong.

Thanks for your reply. Numbers should be coming in in the near future. Thanks. PentaPower.

Measure the working fluid input/output qualities and the output of the driven machine, i.e. electric power or pump output. Then make the thermodynamic calculations. It doesn't matter what size the tubine is, you need to take accurate measurement, make corrections from ambient to standard conditions then apply basic thermodynamic laws.

Thanks for your reply. I'm trying to get all work and calculations done. Within this next week, I should have some results. People say I'm just good at breaking laws, not interpreting them or using them. I'll do my best but will probably get someone else to do that. Thanks. PentaPower.

Mount it on a slat plate with a hinge on the side of the plate that doesn't push down. Put a scale or load cell on the side that pushes down.

Measure the force:

As it stands

With a bar x feet long mounted to the shaft and parallel to the earth

With a known mass somwhere on the bar (this gives you units of torque on the load cell or scale)

Put a load against the Turbine shaft and you have torque and rpm

You now have output power

put the fuel in a bucked and wiegh it over a time slice, you now have fuel usage per power time slice.

This is insanely accurate and it is how I have field tested diesel driven pumps for power usage and efficiency.

Thanks for your reply. I'm not very good at using some formulae, but I'll do my Betz(Freudian slip) to get the results. Thanks. PentaPower.

By the way, have you actually proved that your turbine breaks Betz law, or do you just think it does?

Actually measuring the torque will tell. I suspect that your turbine develops very little usable torque and when you start spinning it under load, rather than spinning it free you will be disappointed by the results.

I also see no reason to believe that it breaks Betz law...

Thanks for your reply. Once testing is done, we will see. It is just the point that no other turbine has taken in all of the forced air. Mine can. The once tested I will be able to see how much energy can be captured. Using low resistance alternators should prove interesting. The ones that the racing team will use are more than likely regular ones. Maybe lots more R&D will be needed. Still our minds can move forwards. Thanks. PentaPower.

Using low resistance alternators should prove interesting.

Use any alternator. For most, you can find published efficiency figures. In the time you've spent writing about this thing, you could have tested it, and presented real test figures.

What concept are you trying to covey with the words "low resistance alternator?" All have low electrical resistance. All are easy to turn, and have low friction bearings.

Thanks for your reply. I'm a person who can easily use words. I'm not the best at building things which take a bit of know how. I have been waiting since the early spring for help with my device and finally I think that I will have some answers fairly soon. I just don't really have time like some people. I work from 7 am til 4 pm then from 4 pm til 11 pm and most times on the weekends. My breaks at work are spent looking for answers and help. Sure I am taking a few minutes to write to you all, but I am relying on others to help. I know that that is foolish, but I need the help. When I got the idea(picture of it in my head) I luckily had two hours off on a Sunday watching a movie. My wife thought I was crazy when I was compelled to built it. She said that I was like a mad man. Well, I built it and then had to go to work. I got home at 11pm and went to bed. The next day was Monday and at 7am was at work. That day is when I met my partner. I showed it to him on my break and we were off to the races. The only time right now to devote to my turbine is limited. I would love to be able to only work an eight hour day and then go home and play baseball, go for a walk, spend time with my children, or devote time to my turbine. This is why this generation is having a few problems. People need money(lots of) to survive. When this thing(turbine) kicks in, one of my goals is to make it easier for people. We all have great minds, it is just that we can't all spend time to use them. Thanks. PentaPower.

A couple of years ago I met an old engineer who, as you, wanted to show that Betz' law is not valid. He found a man with money and enjoyed a couple of years with a big income till all what he designed did not give the results he and his financial support expected. Unfortunately Betz law is -as you said in an other thread- based on "old" physics which should be updated by bright people as you are. I shall make only one remark you write that in your turbine (which looks very alike to a device used already 50 years ago to move ships) air is going in but does not come out! Fantastic you developed a new principle: how to make matter (air) disappear. You should send it as a request for a patent and make a communication to the academy of sciences. Wish you good luck in discovering the new principles of physics!!!!!!

A last comment to obtain the 25000 rpm you should reach a tangential velocity at a diameter of 120 mm of 0.06(m)*2500(rad/s)=150 m/s = 540 km/h. You need a very special car to get it. Or may be your turbine against all principles turns faster than the wind? Again a new aspect with respect to old physics, isn't it?

The choice of aluminum is correct (as you see I am not only negative!) and I would not go direction 316 since the ratio elasticity limit/ specific mass is lower ( ALU = 700/2.8=250 and 316 ≈ 38). If with aluminum you would reach the 25000 rpm using 316 you could not go over 9750 which a lot lower. But those are computations based on old mechanical basics which you could of course demonstrate as being obsolete.

Again good luck

Nick Name