Welcome. I noticed your name on the front page yesterday as newest cult member.
Have you lurked here much? Have you used the Search function?
Other members have talked about, and possibly implemented, this before. I'm skeptical — search for Koenig-Fachsenfeld tearing edges. Or box cavities. Or vortex generators.
This is known to work. It could be truncated to the length added by your wing. The motherload of work on the aft end is at:
http://ecomodder.com/forum/showthrea...rag-33568.html
Unfortunately it has been bit by the Photobucket bug. There is a browser extension to fix that but I don't have it. My own suggestion, since you're an aeronautical engineer (airframe or powerplant?), would be
Coanda nozzles.
The reason I say this is that the rear engine configuration provides a ducted flow of heated, at least 1500cfm, air from the cooling system. I think exhaust is best just dumped, it's corrosive.