Turbofan Duct
Hi all
I'm wondering: what is the main purpose of the turbofan duct? If it has certain effieciency factor, can't we put the same duct around the propellers for other smaller airplane, eg. Piper?
And why does the cross section of the duct has to be an airfoil shape?
I ask this because I saw a motor engine for model aircraft, it has a propeller and plastic duct (also an airfoil shape) around it.
Thanks alot
Bonpon2002