Q:

Propulsion system

Can a propulsion system be made by facing two air ionizers towards each other, accelerating the ions with fans, and having them repel each other? Would the force generated be greater than just accelerating normal air (not ionized)?
Something like this:

Thanks in advance

A:

There's one question that needs to be addressed with any form of ion propulsion: what do you do with the opposite charged particles?  In the diagram you've drawn, it's the positively-charged ozone ions that are being used for the propulsion.  The electrons have to have somewhere to go too, otherwise your ionized gas will be electrically neutral and not repel itself.
If you can figure out somewhere for the electrons to go, I'd say this would probably work.  As long as mass with momentum is flying away from a vessel in an anisotropic way, you'll have propulsion.
The real question is whether this form of propulsion can be engineered in such a way that it is competitive with existing forms of propulsion.  
It is also worth asking where on earth such a form of propulsion can be safely used without the very hot exhaust burning stuff up.  I don't think it could be used anywhere on the ground without serious consequences, so it's only suitable for air travel.
It is worth noting that propulsion systems using ions for thrust have been used on spacecraft, most notably the asteroid-exploring Dawn spacecraft.  These engines normally have some sort of metal as their source of ions and the ions are directed using magnets.  Ion engines are notable for their very high specific impulses, or how much change in momentum a given mass of propellant can produce.

