If I had an aircraft that used propellers for movement and took the air from the front running it through a tube that gets very small towards the end, would it have any impact on the speed?
Would the aircraft get faster because the ejected air would be faster then when it got in, similar to a waterpipe that is half closed?
Would it be slower because the compressed air would act like a barrier for the new air that comes in?
Or would the aircraft have the same speed regardless of whether we run the air thrusted by the propeller through our cone or not?