hi kenny
steve reflected my thaughts on sweeping the wing forward.

is there an aronautical engineer and aero dinamist in your area?were do you live?
what you are talking about is an entirely new aircraft.

dont forget the wings are made in two pices..the carbon rods have to be joined in the middle.it is my amator opinion that what the standard plans call for is superior.

building the wing in one pice may give you extra strenth and slightly less weight.
having said that id like to share some information i recived third hand..from the builder of my dragon.he had a conversation with the disigner and this is what i was told he said...the wood alone in the spare caps was strong enough.

steve is the most experianced pilot in the dragon....steve have you ever flown heavy,with balast?.....will kenny enjoy seeking micro lift in a standard dragon?

kenny reserch flutter....as far as how much balast you will need,you wont know untill its built.

hope i dont sound negative..love your enthusiasm.

russ.

On Sat, Jun 25, 2011 at 6:39 PM, Kenny <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:


I've only had a chance to give it a cursory look, but I think I can understand most of it. Again, I'm a structural analyst, I just need a little help with the aero, and maybe configuration implications of any change. BTW, would there be any issue in just scaling it up 3-5% and then re-running the numbers again on it? I'm thinking I could scale up everything except cockpit width (to help keep the total drag down (less area)). That way I would have to worry about the forward-sweeping wing (though you could probably sweep it a bit without too much trouble (maybe where the leading edge would be straight out?)). That would assure that the wing cord isn't too small to generate lift not change the stall characteristics, no?



--- In This email address is being protected from spambots. You need JavaScript enabled to view it., Steve Adkins wrote:
>
> I would NOT sweep the wing forward on the Carbon Dragon unless there is considerable redesign of the wing structure to handle the aerodynamic twisting loads or torque stresses at the fuselage juncture.
>
> A search of the web also describes powerful pitching moments and center of pressure movement associated with the swept forward wing ... all of which must be dealt with in the design for flight dynamics.
>
> Many glass gliders use the sweep forward method to provide proper CG and to get the wing roots away from the pilot' head (or passenger's head if a two-seater) ... but their wings are very heavy.
>
> I might add that adding pilot weight coupled with a more forward CG results in a lower speed limit when under tow.
>
> www.continuo.com/windrose/culver.htm ... Transcription of Irv Culver's Analysis for Windrose 15m:
> If you can read this 13 page design analysis by Irv Culver, you may be qualified to redesign the Carbon Dragon wing.
>
> Steve
> S. Steve Adkins