Ion propulsion

[popsik]

How ion thrusters work?
i red about them but i can't understand how it works, and i dont know how to make one simple model

 

[DerStrom8]

Hi popsik
The idea behind an ion thruster is that a thin wire conducts high voltage electricity, and the "sharp" edge (created by the thin wire) causes corona leakage. The corona then is attracted to the grounded foil skirt at the bottom. When this happens, the corona is "sucked" downward, forcing air in the same direction. When this air is blown downward, it thrusts the lightweight frame in the opposite direction, and you have lift.
Does this answer the question at all?
Good luck!
Der Strom

 

[trash]

Newton's third law is where it is at.
For every action there is an equal and opposite reaction.

If you're thinking of the standard triangular shaped aluminium foil ion "levitation" model, then DerStrom pretty much summed it up.
https://www.youtube.com/watch?v=71v5sFu7LT8&feature=related
In all ion engines a particle is given an electrical charge (the wire at the top) and it is then attracted to grid or a target which does not collect the particle.
The acceleration given to that particle is will give an equal and opposite acceleration to the ion engine.

In space the advantage of ion engines is that a LOT of energy can be given to even a single atom. Enough to push a starship.
If a single hydrogen atom is given a velocity extremely close to the speed of light, the assembler that accelerated it will recoil like a
high powered rifle shooting a tiny bullet, but on a much more extreme scale.

And this can also work in reverse. Decelerating particles can be used to generate electricity.
A really nice educational model is a Kelvin generator and they are very easy to build and safe enough for kids to play with.

 

[dumpsterdiver]

A different form of rocket

An ion engine simply uses electric charges instead of heat to accelerate a reaction mass out a nozzle.

 

[squishy36]

It's conceptually the same as throwing rocks off the stern of a ship. Note that the center of mass stays stationary for an isolated craft and ions.