General > General Technical Chat
Mess with your minds: A wind powered craft going faster than a tail wind speed.
electrodacus:
--- Quote from: dunkemhigh on August 30, 2021, 06:16:55 pm ---You keep saying that. Why does it change everything? And in what way?
--- End quote ---
You keep thinking about that, since me making all the thinking seems not to be helpful.
IanB:
--- Quote from: electrodacus on August 30, 2021, 06:15:24 pm ---I posted before the diagram from Wikipedia that shows the pressure differential for an axial fan. You an see P1 and P2 is much higher than PA (ambient pressure)
--- End quote ---
And I linked you to a video of a real experiment which shows the pressure in front of a fan is lower than the ambient pressure. Which means that diagram does not show what you think it shows.
Why do you keep asking us to do experiments, but when I show you an example of an experiment you refuse to believe it?
electrodacus:
--- Quote from: IanB on August 30, 2021, 06:48:17 pm ---And I linked you to a video of a real experiment which shows the pressure in front of a fan is lower than the ambient pressure. Which means that diagram does not show what you think it shows.
Why do you keep asking us to do experiments, but when I show you an example of an experiment you refuse to believe it?
--- End quote ---
You have no idea how to interpret that experiment and neither the person that made the video.
While Wikipedia is not always a reliable source of information it is at least a step above average people posting a video on youtube not understanding what they are testing.
IanB:
--- Quote from: electrodacus on August 30, 2021, 07:05:57 pm ---You have no idea how to interpret that experiment and neither the person that made the video.
--- End quote ---
It does not need to be interpreted to observe the simple fact that it demonstrates, which is that the pressure in front of the fan is lower than the ambient pressure.
The fact is that fans and propellers do not compress air. What they do is accelerate the air passing through them. This acceleration generates a reaction force that drives the propeller forwards.
Unfortunately, if we show you the experiment where the cart in your diagram moves from left to right, you will dispute that too, and will claim that experiment also is being misinterpreted. So it's not worth our time showing you results that you will refuse to believe.
electrodacus:
--- Quote from: IanB on August 30, 2021, 07:37:52 pm ---It does not need to be interpreted to observe the simple fact that it demonstrates, which is that the pressure in front of the fan is lower than the ambient pressure.
The fact is that fans and propellers do not compress air. What they do is accelerate the air passing through them. This acceleration generates a reaction force that drives the propeller forwards.
Unfortunately, if we show you the experiment where the cart in your diagram moves from left to right, you will dispute that too, and will claim that experiment also is being misinterpreted. So it's not worth our time showing you results that you will refuse to believe.
--- End quote ---
I almost feel like I'm talking with flat earthers and so nothing I can say will convince you. The best I can suggest is you do the experiment and see that what happens is exactly what I predict.
So have a vehicle as shown in my diagram (not flipped) and observe that whatever you do in therms of gear ratio the vehicle will move from right to left.
The flipped vehicle is completely different due to the way the forces act on the vehicle are different and that vehicle can travel in both directions based on gear ratio. That flipped vehicle represents the analog of the propeller vehicle where propeller is the generator (not a fan) and so it drives against the wind direction.
What you can observe on that one if you want is that it can not exceed the wind speed meaning vehicle relative to stationary ground can not travel faster than the speed of the treadmill.
So the vehicle in my diagram is very different from the vehicle that was demonstrated where vehicle was flipped.
I will like to show the below diagram but hopefully that will not create even more confusion for you. That shows what happens when you flip a vehicle and top of the wheel will touch the surface instead of the bottom of the wheel.
This diagram was to explain Derek what his wheel vehicle with the floor and lumber represents.
In any case just build the vehicle in my original diagram and experience the fact that vehicle will always move from right to left. This will be analog to getting a flat earther in to space to see for himself that earth is an approximately spherical object.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version