Groove gear fairing

[Birdseyeview]

Foxbuilder, Thanks for the link to that very interesting video on drag reduction. The principles revealed in that video would seem to confirm your suspicion that I may have inadvertently increased drag by creating a drag increasing "nozzle effect" between the fuselage skin and the trailing edge of my fairing. Without testing this in a wind tunnel its impossible to tell how much drag there was before and after my mod but the video makes sense and gave me an idea on how to eliminate the "nozzle effect" drag at the trailing edge. My idea would be to change the cross section of the fairing from the symmetric cross section I currently have to one with a flat top surface running parallel to the skin of the airplane and to make the bottom surface with all the curved streamline in it from front to back. That should reduce or eliminate the drag caused by the nozzle effect at the trailing edge. I think my next attempt to construct such a fairing will make for another fun project. Thanks again for the tip.

[Eric Page]

Larry, if I understand your proposal correctly, it seems to me that your idea would create an inverted wing cross section that would generate downward lift, counter to the main wings. Also, any parasite drag reduction the fairing creates might be replaced by induced drag, both from the downward lift of the fairing and from the increased wing lift required to offset the fairing lift.

Just thinking out loud here. I could be out to lunch; as I have proven in multiple forum posts, I am not an engineer!