airframe terms and design issues
06-03-2006 | 05:14 PM
#1
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From: Encino,
CA
airframe terms and design issues
Greetings,
I recently got back into rc aircraft and have been designing and building a few of my own. I've been looking into building a forward swept wing with a fuselage/pod hung out front off of a couple of carbon fiber rods. I'd like to place 2 control surfaces on it (something akin to a vtail accept up at the nose of the aircraft, and or perhaps towards the center of each wing).
I've been looking for a few design forums and or interactive irc style channels and not having any luck. Web searches are difficult because I'm not sure of the correct terminology for what I'm hoping I can design. First off will the plane/glider fly in this configuration (assuming I get the cg correct)? Also when a vtail is placed on a planes nose are they considered canards, or does there extreme angle from the horizontal, and non central pivot control change the term? rudder or vtail style control surfaces on the wings themselves do they have yet another name? Does anyone know of a generic airframe style reference sheet (or more useable google search terms to find the info I'm looking for?) Any help in reguard to these nonstandard terms/designs would be most helpful
I recently got back into rc aircraft and have been designing and building a few of my own. I've been looking into building a forward swept wing with a fuselage/pod hung out front off of a couple of carbon fiber rods. I'd like to place 2 control surfaces on it (something akin to a vtail accept up at the nose of the aircraft, and or perhaps towards the center of each wing).
I've been looking for a few design forums and or interactive irc style channels and not having any luck. Web searches are difficult because I'm not sure of the correct terminology for what I'm hoping I can design. First off will the plane/glider fly in this configuration (assuming I get the cg correct)? Also when a vtail is placed on a planes nose are they considered canards, or does there extreme angle from the horizontal, and non central pivot control change the term? rudder or vtail style control surfaces on the wings themselves do they have yet another name? Does anyone know of a generic airframe style reference sheet (or more useable google search terms to find the info I'm looking for?) Any help in reguard to these nonstandard terms/designs would be most helpful
06-04-2006 | 01:22 PM
#2
RE: airframe terms and design issues
Becareful. It sounds more like you're trying to make an arrow fly backwards. Having the horizontal tail forward produces a canard shape and the rules for dealing with that are fairly well known. But you will not be able to put the vertical tail forward of the wing's MAC. That would be like flying an arrow backwards. The model would constantly try to swap ends.
Also with a swept forward wing you need to ensure that the control surfaces are decently spaced lengthwise from the MAC (that's Mean Aerodynamic Chord). For example putting the elevator surface within the V of the wing could well produce an arrangement where the elevator is within the range of the MAC of the wing and it produce either minimal or NO pitching control. In such a case you'd be better off with the elevator function on the center trailing edge of the main wing.
Also with a swept forward wing you need to ensure that the control surfaces are decently spaced lengthwise from the MAC (that's Mean Aerodynamic Chord). For example putting the elevator surface within the V of the wing could well produce an arrangement where the elevator is within the range of the MAC of the wing and it produce either minimal or NO pitching control. In such a case you'd be better off with the elevator function on the center trailing edge of the main wing.
06-04-2006 | 06:41 PM
#3
Senior Member
RE: airframe terms and design issues
Many years ago there were a couple of articles in MAN about design of free flight swept-forward flying wings. They ended up with a large high rudder, elevons at the rear, symmetrical airfoils and washin at the forward tips.
If you look through your old Model Aviation magazines at the Editor's column, you will find a picture of Bob Hunt holding a bare bones airplane similar to what you are talking about, but for control line stunt.
If you look through your old Model Aviation magazines at the Editor's column, you will find a picture of Bob Hunt holding a bare bones airplane similar to what you are talking about, but for control line stunt.
