drkohler said:
Sqrl said:
The site is undergoing some big changes right now so there are some new bugs that need to be ironed out. ioi should hopefully have the more annoying stuff fixed by the end of the week.
On Topic: The idea of increasing the speed of the treadmill is an interesting one and will technically work. But the amount of extra speed required to offset the immense amount of thrust this thing will be producing has me cringing at the thought of building such a treadmill. Since only a small fraction of the treadmill's power is actually turning into deceleration for the plane it will take a huge amount of belt speed to counteract the accelerating plane.
I won't hazard an exact guess but it seems like the belt could be required to approach mach speeds to accomplish this task. It really depends on what the actual percentage of treadmill energy is lost in spinning and the percentage that ends up in the frame. It won't be a constant percentage over a range of speeds either, which complicates things. And iirc the faster the wheels are spinning the less energy is actually transferred into spinning and more is lost in heat and in the frame, so that aspect at least is working in our favor.
Let me know if I am missing something. |
Agreed. The only solution I see is to actually test the myth is a rotating drum and a fast feed back system to keep the plane (on auto pilot, no real pilot is that suicidal) on top of the wheel. You can pretty much slowly speed up the drum to senseless speeds, but then at some point even the best tyres will probably explode before the take-off speed is reached. The more I think about it, the less likely the experiment becomes a real possibility.
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There are some advantages to a drum system. It allows us to ensure that the surface the wheels are coming in contact with is extremeley smooth and this allows us to go with solid wheels instead of inflated wheels. As a result there is no chance of an exploding tire.
However we still have a problem similar to that of most helicopters. In helicopters they can have issues with extreme stress on the the leading rotors as they swing around to the front of the helicopter. This is caused by the rotor's combined swinging speed and speed of the helicopter approaching mach speeds (aka transonic). The result is large amounts of instability in pressure around the rotors as they swing to the front and even more instability as that pressure is removed (all sudden pressure changes causes instability for a rotor, regardless of increase or decrease).
I think a similar stress problem could appear if the wheels are required to spin that fast, but I feel like there is bound to be a better way around this than what we are looking at.
