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| Kleinstein:
The point is not capacitor vs inductor, the point is that it there is any energy stored in the pressure field is dissipates quite fast to the environment, not to the vehicle. The time scale is so short, that even 1/10 of a second is a long time. So the experiments shown are well long enough to be in essentially steady state. Aerodynamics is a bit difficult, so I avoided going in the details there. The intuition says that if all the energy would rise when the vehicle would go faster, so the ernergy storrage would be more like adding a small part to the energy when moving and thus would work in the other direction. So the energy in the air would be available only when the vehicle slows down and can thus not increase the speed of the vehicle. So I doubt the air pressure could "help" (explain the higher speed) even at the bery short time scale. The problem with the mis-understanding of paper vs treadmill could be solved if you tell us why the two should be different or how the vehicle could notice the difference. Most of us have a problem spotting the difference. |
| electrodacus:
--- Quote from: Kleinstein on September 02, 2021, 06:34:22 am ---The point is not capacitor vs inductor, the point is that it there is any energy stored in the pressure field is dissipates quite fast to the environment, not to the vehicle. The time scale is so short, that even 1/10 of a second is a long time. So the experiments shown are well long enough to be in essentially steady state. Aerodynamics is a bit difficult, so I avoided going in the details there. The intuition says that if all the energy would rise when the vehicle would go faster, so the ernergy storrage would be more like adding a small part to the energy when moving and thus would work in the other direction. So the energy in the air would be available only when the vehicle slows down and can thus not increase the speed of the vehicle. So I doubt the air pressure could "help" (explain the higher speed) even at the bery short time scale. The problem with the mis-understanding of paper vs treadmill could be solved if you tell us why the two should be different or how the vehicle could notice the difference. Most of us have a problem spotting the difference. --- End quote --- You asked for the electrical analog so I was assuming you understand how an inductor stores energy and that is an almost perfect analog of the pressure differential energy storage works. The magnetic field around the inductor can also collapse in a fraction of a second depending on the inductor inductance and current but it can also last for many seconds. The propeller analog equivalent is an inductor parallel with a capacitor and the vehicle is another capacitor. While the inductor discharges it can charge this two capacitors than then continue to push some current trough the inductor maintaining the magnetic field around the inductor for a bit longer. In any case it is demonstrated in both Blackbird and on treadmill model that there is enough energy stored to power the vehicle for at least about a minute in the case of blackbird and at least a few seconds for the treadmill model. You will have no choice but to agree with that we can agree that the vehicle in my diagram can not advance from left to right without energy storage equivalent of pressure differential. It seems my power equation is not convincing you while there is nothing wrong with that so best bet is for you to test what is shown in my diagram and see for yourself that vehicle can not travel from left to right. |
| Kleinstein:
--- Quote from: electrodacus on September 02, 2021, 06:15:37 am ---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. --- End quote --- That simple "fomula" (it is more like an agumant in words) is simple, but simply wrong. If you argue like this, it could also no more rigth to left and nothing would move at all. If you really want to argue with power and not force, you have to add the relative movement of the platforms as a 3rd power - and it is a powerfull one. It adds to the power of the generator. Than the formulas suddenly no longer are so simple and the result is that the vehicle does move to the right. The picture is much easier to understand with only looking at the speeds and use a fixed gear ratio. This formula(s) are really simple (and they are actual formulas) and give a definitive answer: with the right gear ratio you can go left. The prop will not slow down the collaps (desappears as sound) of the pressure field very much - we don't care about a factor of 10, it is still way faster than the experiment. |
| cbutlera:
--- Quote from: electrodacus on September 01, 2021, 11:18:19 pm ---You did not took energy from the aeroplane. --- End quote --- You seem to have changed your mind. In your previous message you not only agreed that I did take energy from the aeroplane, you also correctly calculated how much energy I took. --- Quote from: electrodacus on September 01, 2021, 08:17:36 pm ---I may not have been very clear. In your tough experiment there are two sources of energy both contributing to your increase in kinetic energy. Out of that 14035J you contributed 35J and the plane contributed with 14000J. --- End quote --- You then go on to say. --- Quote from: electrodacus on September 01, 2021, 11:18:19 pm ---If the aeroplane did not had a constant speed controller say maybe even engines turned off then you will have slowed down the aeroplane while you where traveling at 1m/s. --- End quote --- Yes, that's right, you've got it! You have identified the source of the additional energy that I took, and the reason why conservation of energy is not being broken. When I started walking at 1 m/s, I gained 14,035 joules of kinetic energy (in the frame of reference of the ground). The aeroplane provided 14,000 of those joules, and in doing so lost 14,000 joules of its own kinetic energy, by slowing down very slightly. The entire system of me plus the aeroplane only gained the 35 joules of kinetic energy that my muscles produced. So you do agree that I have taken energy from the aeroplane after all, and that I did it while moving slightly faster than the aeroplane. |
| Brumby:
--- Quote from: electrodacus on September 02, 2021, 06:15:37 am ---... power at motor wheel ... ... power at generator wheel ... --- End quote --- Still with the wheels. :palm: It is pointless to try and explain what is actually going on when you consistently present flawed logic and dismiss any explanation which disagrees with your preconceptions. For this discussion to have been through so many iterations without you having conceded a single point of any argument that even looks like it challenges your stubbornly held position, then your objectivity is - quite simply - non-existent and your understanding of physics is both narrow and flawed. So, I'm wondering ... did you try for a job at SpaceX without luck - and now you're working for Blue Origin? Edit: Amended the above. Blue Origin have actually got something off the ground. |
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