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| Mess with your minds: A wind powered craft going faster than a tail wind speed. |
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| Kleinstein:
If working at all, energy storage in the pressure field around the vehicle is only short time. This is a bit like tryoing to store energy in a rather leaky capacitor. The pressure will not only push the vehicle, but just dissipare as sound to all other directions. The time constant for the "discharge" of the hypotetical energy storrage is on the order of dimensions divided by the speed of sound. So for the balckbird this are some 5 m divided by 330 m/s, some thing like 2/100 seconds. So any energy stored would vanish fast, even if the order of magnitude estimate is off by a factor of 2 or Pi it is just a faktor of 1000 to short to keep significant energy. The argument is about the time scale, so no need to calculate the energy - after some 100 time constants there is essentially nothing left, no matter how much was there to start with. |
| electrodacus:
--- Quote from: bdunham7 on September 02, 2021, 04:06:35 am ---OK, please describe the area or whatever that stores the energy--the physical dimensions, the method of energy storage (pressure?), etc. I'm not getting that part. --- End quote --- There is a volume containing that stored energy about half of it in front and the other half on the back of the propeller. See the shape of that in that propeller graph on Wikipedia. And yes pressure differential is what the energy is stored in to. I'm not a mechanical engineer and I barely passed my fluid dynamics exam at university so sure not the most qualified to precisely calculate the exact amount of energy stored here and the efficiency of this energy storage device. I'm sure there are simulation tools that can based on correct input data provide fairly accurate results sort of analog to a spice based analog simulation for electronic circuits. I'm sort of surprised that I sis not see such a simulation for this types of vehicles after all the discussion. I guess some have tried and since they did not see the expected results they did not made the result known as there where thinking that do not know how to properly simulate that. But not sure how we got to discus energy storage when the treadmill vs paper discussion is not solved. I think explaining pressure differential energy storage is more complex than the wheel only vehicle diagram solution and nobody confirmed that they agree with my claim that vehicle can not move from left to right. That when understood will demonstrate that exceeding wind speed without energy storage is not possible and then we can discus about more seriously about the pressure differential energy storage. |
| electrodacus:
--- Quote from: Kleinstein on September 02, 2021, 05:32:54 am ---If working at all, energy storage in the pressure field around the vehicle is only short time. This is a bit like tryoing to store energy in a rather leaky capacitor. The pressure will not only push the vehicle, but just dissipare as sound to all other directions. The time constant for the "discharge" of the hypotetical energy storrage is on the order of dimensions divided by the speed of sound. So for the balckbird this are some 5 m divided by 330 m/s, some thing like 2/100 seconds. So any energy stored would vanish fast, even if the order of magnitude estimate is off by a factor of 2 or Pi it is just a faktor of 1000 to short to keep significant energy. The argument is about the time scale, so no need to calculate the energy - after some 100 time constants there is essentially nothing left, no matter how much was there to start with. --- End quote --- The pressure differential energy storage is equivalent to an inductor while the flywheel kinetic energy storage and vehicle kinetic energy is equivalent with a capacitor. So while the inductor (pressure differential) is discharging the capacitor (kinetic energy) is charging. |
| IanB:
--- Quote from: electrodacus on September 02, 2021, 05:40:32 am ---But not sure how we got to discus energy storage when the treadmill vs paper discussion is not solved. --- End quote --- It is solved for everyone except you. --- Quote ---I think explaining pressure differential energy storage is more complex than the wheel only vehicle diagram solution and nobody confirmed that they agree with my claim that vehicle can not move from left to right. --- End quote --- Everybody, without exception, disagrees with your claim. --- Quote ---That when understood will demonstrate that exceeding wind speed without energy storage is not possible and then we can discus about more seriously about the pressure differential energy storage. --- End quote --- You are doing this backwards. Once understood that the vehicle can move from left to right, it then becomes possible to understand that exceeding wind speed without energy storage is also possible. If you start by assuming something is impossible, rather than trying to understand how it works, you become stuck in a hole you cannot get out of. |
| electrodacus:
--- Quote from: IanB on September 02, 2021, 06:05:40 am ---You are doing this backwards. Once understood that the vehicle can move from left to right, it then becomes possible to understand that exceeding wind speed without energy storage is also possible. If you start by assuming something is impossible, rather than trying to understand how it works, you become stuck in a hole you cannot get out of. --- End quote --- I get your perspective. The problem is that you did not proved either with a formula or with a test that what I say about vehicle in my diagram being unable to move from left to right is incorrect. My formula is super simple power at motor wheel is smaller always than power power at generator wheel since generator wheel is what powers the motor wheel thus easy conclusion that vehicle can not advance from left to right. And what it was showed in tests is completely different from my diagram as there was no treadmill involved. And yes I'm aware you think a piece of paper dragged is the same as a treadmill but it is not (not even close) and you will see that if you will do the experiment. And the flipped vehicle is the exact same thing as the dragged paper. I do not want to order some toy wheel vehicle and build a simple treadmill just to demonstrate this simple point. It will take probably a few weeks to get the parts at my remote location and then I'm left with some useless stuff. But any of you that already has the wheel vehicle and maybe even a treadmill or can build a simple manual treadmill even out of paper can do the test and prove me wrong. I even offered to provide compensation if I'm wrong and you prove that. |
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