NACA Duct for RC airplanes, well anything really.....

thingiverse

Still building an Ansley Peace Drone. Decided to put some NACA ducts on the sides to keep the innards nice and cool. :) Pretty close to a standard NACA duct. I copied the drawing from here as close as I could. http://www.formula1-dictionary.net/naca_duct.html The scoop is optional. But it gives it a nice finished look. Mine are just fit flush with the foam. Let the front of the scoop poke out a little for more air. At the expense of more drag. Print with them standing up with the widest end of both parts down and supports will be minimal. I orientated the STL for that. ."THE BEER-WARE LICENSE" (Revision 42): https://www.thingiverse.com/kwg08/ wrote this file. As long as you retain this notice you can do whatever you want with this stuff (for non profit uses only.) If we meet some day, and you think this stuff is worth it, you can buy me a beer in return.