I invented a flying engine moving entirely by magnetic forces (such as the force
ID: 1374327 • Letter: I
Question
I invented a flying engine moving entirely by magnetic forces (such as the force related with magnetic field of the Earth).
See http://porton.wordpress.com/2011/12/23/magnetic-vehicle/
The question is, can we build an engine of this type which is enough powerful to actually fly?
The question is both about the mechanical engine described in the post above and about a hypothetical (not developed by me in details) purely electronic version.
My question is: Describe operating characteristics of these kinds of engines.
Explanation / Answer
No such engine can exist--unless you custom-tailor your magnetic field.
Any such engine you build will need a current loop--since current requires a closed circuit to flow.
A current loop never has any force on it in a uniform magnetic field{*}. It can have a torque, so at max you can create a device that spins.
If you want something to levitate, you need to generate a nonuniform magnetic field. A large magnet on the ground is one way to do this, but it leads to instability. And you'd have to keep the magnet with you wherever you went, so you effectively have to drag a large magnet along the ground to make a teensy thing fly.
Of course, you can lay out the magnet like a track. Which has already been done in maglev trains.
enter link description here
In a maglev train, there are magnets in the track, and electromagnets at the bottom of the train (or is it the other way around? Doesn't really matter here) The electromagnets rapidly switch polarity.
In the diagram above, you can see that the train will be pushed towards the left. If you think a bit, you way also notice that, due t the symmetry of the situation, once the train is left, it will be pushed towards the right. But, in the time it takes for the train to be pushed left, the polarity of the electromagnets switches, and the train gets pushed further left.
Here, the magnets serve two purpses: they make the train go, and the levitate it (reduces friction). Maglev trains are one of the fastest type of trains and have been in use in many major cities for quite some time now.