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| Mess with your minds: A wind powered craft going faster than a tail wind speed. |
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| Brumby:
--- Quote from: electrodacus on December 24, 2021, 05:41:59 pm --- --- Quote from: Brumby on December 24, 2021, 11:22:34 am --- --- Quote from: electrodacus on December 24, 2021, 12:15:56 am ---Yes the entire swept area of the propeller acts as a barrier keeping the low and high pressure volumes separate. --- End quote --- How does that work? (I think this needs a diagram.) --- End quote --- Here it is. I posted this several times but people try to ignore it or say it is incorrect. --- End quote --- The diagram might be correct for what it's describing - but it is does not match what is happening with the Blackbird. The first thing I see is that there is no confinement surrounding the Blackbird propeller - and that is clearly an important part of the diagram you presented. Does this not compromise what you are saying? |
| IanB:
--- Quote from: electrodacus on December 25, 2021, 12:57:45 am --- --- Quote from: dunkemhigh on December 25, 2021, 12:11:34 am ---No, the battery is still driving the motor. It is simply a combination of 1 and 2: wind blowing in the sail, sail being moved along the vehicle. Do you agree the vehicle ground speed would be close to 3m/s? --- End quote --- Yes but this just proves my point that an energy storage device is needed to exceed wind speed. --- End quote --- Every time you dodge the question like this and try to change the subject, it just proves you are playing games. Either answer the question, or stop playing. |
| electrodacus:
--- Quote from: Brumby on December 25, 2021, 01:11:12 am --- The diagram might be correct for what it's describing - but it is does not match what is happening with the Blackbird. The first thing I see is that there is no confinement surrounding the Blackbird propeller - and that is clearly an important part of the diagram you presented. Does this not compromise what you are saying? --- End quote --- There is no confinement with that axial fan I used as example. You just misinterpreted the diagram. That is exactly applicable to blackbird. What you see there is the approximate boundary (fluid at rest and in motion) and no physical barrier. And yes since there is wind the other fluid will also be in motion but at different speed. |
| PlainName:
--- Quote from: electrodacus on December 25, 2021, 12:57:45 am --- --- Quote from: dunkemhigh on December 25, 2021, 12:11:34 am ---No, the battery is still driving the motor. It is simply a combination of 1 and 2: wind blowing in the sail, sail being moved along the vehicle. Do you agree the vehicle ground speed would be close to 3m/s? --- End quote --- Yes but this just proves my point that an energy storage device is needed to exceed wind speed. --- End quote --- OK, so now we go back to scenario 2 and replace the moving sail with a static propeller. Recall that: * There is no wind * The propeller is powered by a battery If the speed of the propeller wash is 1m/s, do you agree that the vehicle will move forward at around 1m/s? |
| electrodacus:
--- Quote from: dunkemhigh on December 25, 2021, 10:11:00 am --- --- Quote from: electrodacus on December 25, 2021, 12:57:45 am --- --- Quote from: dunkemhigh on December 25, 2021, 12:11:34 am ---No, the battery is still driving the motor. It is simply a combination of 1 and 2: wind blowing in the sail, sail being moved along the vehicle. Do you agree the vehicle ground speed would be close to 3m/s? --- End quote --- Yes but this just proves my point that an energy storage device is needed to exceed wind speed. --- End quote --- OK, so now we go back to scenario 2 and replace the moving sail with a static propeller. Recall that: * There is no wind * The propeller is powered by a battery If the speed of the propeller wash is 1m/s, do you agree that the vehicle will move forward at around 1m/s? --- End quote --- Replacing the moving sail with a propeller will not be the same thing if the propeller is not powered by something. And since you do not have a battery and you do not accept there is an energy storage device (pressure differential) then there is nothing that can power the propeller other than the kinetic energy of the vehicle but taking energy from that will result in reduced vehicle speed. So propeller will still rotate but slower and slower same thing that actually happens after the vehicle used all the pressure differential and vehicle starts to slow down. |
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