Is Negative Drag a Real Concept in Fluid Dynamics?

[mista_chewey]

my first post but i had to get this out before i explode!
this has been bugging me to hell

on this other forum i visit. there are a bunch of people insisting on "negative drag"
is there such a thing?

from what i understand drag is a force acting on an object moving through a fluid.
and thrust is a force propelling the object through the liquid.

so negative drag would be a force enacted on the object by the fluid in the direction of movement. so the object will be propelling itself wouldn't it?

there is also another statement that says "thrust IS negative drag"
thrust is constantly trying to over come drag so how can they be the same thing?

so is it the same thing?

 

[FredGarvin]

Negative drag is not a proper term. The word "drag" has a very specific meaning associated with it along with a mathematical/engineering definition. The engineering definition alone prevents the usage in the way that you are saying. There is absolutely no reason to use a term like "negative drag." Would any of these people say something like "you need to negative push to open the door?"

They are the same thing in that they are both forces, but that is the extent of their similarities.

 

[mista_chewey]

so my understanding of thrust and drag is correct right?