4 ms·
The propeller is being used a forward motion compensator. At a standstill, the wind just acts on the entire vehicle including the stationary propeller, and set
by pengaru 5y ago
The propeller is being used a forward motion compensator.
At a standstill, the wind just acts on the entire vehicle including the stationary propeller, and sets the whole thing in motion.
Without the propeller, going directly downwind would be limited by the speed of the wind acting directly on the vehicle which otherwise lacks any relevant moving parts for the wind to act on.
By adding the propeller, driven by the forward motion via the wheels, a part of the vehicle now moves backwards (imagine the cross-section of a propeller blade as it spins, its intersection with the wind travels backwards into the wind) to compensate for the forward movement, giving the wind something to act on even when the vehicle travels faster than the wind.
- cblconfederate 5y agoI wonder how one would go about making such machine that would work in zero gravity. Without friction, something else would have to convert part of the wind force to propeller torque. Maybe small turbines could be added that would spin according to apparent wind (forward or backward) and spin the propeller to generate additional lift.
- pengaru 5y agoFun thought exercise, but are there any practical scenarios where one has wind but no gravity?
- cblconfederate 5y agosolar wind
- pengaru 5y agoIs that really practical considering the already high velocity of the particles? If you matched the downwind particle velocity (>100km/s?) it seems unlikely any mechanical motion compensator could move fast enough to make any significant gain to be worthwhile... but I'm no expert, maybe I'm missing something obvious.