What is the smallest, powerful, and most effecient version of thrust?

[angushall19]

I thinking of thrust ideas and I wonder if in proportion to fuel usage amount and the power to size ratio it makes up whick will be the best?

[TheGeckomancer]

I am by no means an expert in this field but I think you need to specify circumstances. I know efficiency and effectiveness change ENTIRELY based on circumstances. There is a thing called an ion thruster that can get up to 80% thrust efficiency, but from what I know about it the thrust is insanely small. Which is FINE for space travel, where forces that reduce momentum are minimized. In any atmospheric condition that that ion thruster becomes less than worthless.

[Externet]

Try 0.22 long-rifle bullet without the lead ? That is the smallest caliber, I think.

[arc]

[fresh]

WOW! arc, where did u get this little creature from ?

[pavelcherepan]

I thinking of thrust ideas and I wonder if in proportion to fuel usage amount and the power to size ratio it makes up whick will be the best?

 

You're asking about two things that sort of work against one another. High TWR with the current technology is achieved in very powerful engines (rocket engines), while high efficiency engines are very low thrust. So you really need to define what exactly you want.

 

Looking at this chart from Wikipedia (Thrust-to-weight ratio article) you can see that from the currently known technologies for rocket engines nuclear fission and liquid/solid fuel engines are the best. Obviously, there are no current fission rocket engines but from initial studies back in 1970s to 1990 show that they can have really good TWR combined with very high Isp.