I am attempting to design a "flying saucer." The saucer is an ellipsoidal-ish body with a RC drone inside. I plan to allow for air access to the rotors as shown in the rudimentary diagram below:
I am pretty sure that the drag on the air flowing through the intake and through the body of the flying saucer will reduce the thrust capacity of the drone. Can anyone confirm this? Are there any other considerations I should keep in mind (maybe there's a reason helicopters don't have a big tube surrounding the lift rotor)? I want the flying saucer to behave like a slow, mellow RC drone (I don't really want high speeds or elevations).