HELP on deltawing airfoil

[Vince Ruhe]

Could anyone give me some ideas on the most efficent arifoil for a deltawing style edf jet?!?? How far back from the le do u put the thickest area? Would a flat bottom style work or should I use one with some undercamber? The proposed jet is a scratch built SR-71 with 2 EDF-50's, call me crazy! The wing will be shaped from bluecor with the main fuse being a 2" tube with foam to shape it. Am I pointed in the right direction, or will I bite the dirt?
If it does fly I will give all the probs I ran into.
I would like to thank all of you for the help you have given me so far.

[Sparky Paul]

The problem with very long chord short span planes like the Blackbird is the ease with which they depart. The airspeed MUST be kept very high. Pull some g.. not a lot, and the airflow seperates, the plane stalls, slows down, and remains stalled all the way into the ground.
The airfoil shape won't matter much. It's a flat plate in essence, due to the long chord. Keep your speed up.

[Bare]

Hehhh. Seems EVERY newbie wants to model a SR71. It is seductive but a Poor choice.
The real version barely flies, all it does is high speed high altitude straight flights.. it's a spy/camera platform.. nothing more nothing less.
Even at model scale the thing will need to fly straight and fast, simply to stay airborne, great if you fly on the open prarie, a bit more difficult in the usual flying fileds where you need lotsa extra power to constantly turn .
But don't let me discourage you, perhaps yours will the one in hundreds that actually gets as far as the flying field.

[fumblefingers]

There was a design published in the late 60's of a delta called the NUTRINO. This plane had a fairly thick airfoil, I would estimate about 3"at the thickest point, to about 1" at the tips. While it was a delta, it had extensions at the wingtips which were about 6"each with a constant chord of about 9". This plane had a total span of about 50", and would slow down, with the nose level, very well. This is unlike the "flying boards" which seem to prevail today, which seem to just hang on the prop. It was published in 2 versions, one built-up, and the other was foam. It was published in a magazine that is now out of business, but I don't remember the name. I don't know if this will be of any help, bit I would like to obtain a smaller version suitable for a speed400 motor.
john

[Flypaper]

I still fly a Hustler delta I built back in the 60's. Very thick wing, very sharp LE at the root, very blunt LE at the tip. Takes off and lands with the nose way up like a 747. No tipstall. All depends on the design.K.B 20 DF engine.

[Shakey Jake]

Just picked up a July issue of RC Modeler. It has a construction article on the SR=71 Blackbird for 40 size glow. I was interested because of the mid wing prop mounting feature. Could be jiggered around for EDF I'm sure. Uses a flat bottom wing for simple construction. He has apparantly worked out the crazy flight problems. Will do all the basic loop, roll, inside & out. Doesn't stall, just does a nose high wobble. Take a look. Looks good to me.

Shakey