ORIGINAL: CrateCruncher
PR,
What did you do to improve the low speed performance of the Giles? I have a .40 size plane that I have to land like a rocket or it gets all loosy goosey on final(51" span, 10.5"chord, 14% semi).
Nice to hear your son has an interest in engineering. Thats quite remarkable these days with so much negativity toward it in American pop culture: style-retards, nerds, etc. I figured the younger crowd all want to do "mergers and acquisitions" or "CSI-SVU" or something.
Crate,
One of the most important things I found is that symmetrical airfoils between 10%-15% experience high-speed stall at around 15-degrees AOA. At 15-degrees and more, the airflow detaches from the upper wing surface and there is no more lift. We cannot prevent that. We have to work with it.
The first thing I did was keep a low or acceptable wing-load. Second, locate the CG properly. Third, setup elevator throws. I keep my wing-load at around 25. I was really shooting for 23 but I could not accomplish it using the top-end engine. I setup the CG so the nose of the airplane does not climb or dive while banking and I setup the elevator to operate just below 15-degrees AOA. This does not mean the airplane is not able to do a tight turn of 180-degrees in a small radius. So, the way I understand it, the wings have to be at less that 15-degrees AOA to keep flying while the airplane as a whole is very responsive because of the way the CG is located. Does it make sense? Think about the gradient or rate of change of AOA over wing flow. Keep the gradient low. It is all aerodynamics.
Send me a PM if you want to go over the setup with you.
Pedro