Re: Q-talk 155 - Stay Safe. . . .


One Sky Dog
 

Hi Ray and Trever,

I fly Dragonflies with GU canards, they are flown at a lighter wing loading than Q's so they may fly different. I resisted putting the vg's on for similar reasons. One day as I was boarding an airliner I noticed a bunch of vg's around the tail. Start looking a lot of airplanes have them they work to fix things that need a tweak. The USA B-52 has hundreds of them all over the place. In my opinion I think a separation bubble starts at the root of the elevator and is always there but grows span wise as contamination disturbs the laminar airflow on the recovery section of the airfoil. The vg's prevent that bubble from forming at the aileron hinge line. The GU does have a better L/D than the LS1. The vg's are at 50% chord and are below the peak on the airfoil. This seems to not cause additional drag and did not slow my plane down.

It is a lot faster and easier If you want to get flying faster. My $0.02 worth.

Regards,

Charlie Johnson a.k.a. One Sky Dog
Flying 187CD Dragonfly/Corvair ,phase 1 test flight, 6 hr. Airtime 15 hr engine runtime

On Oct 30, 2012, at 2:01 AM, "johnogr300" <johnogr@...> wrote:

Hi Trevor.
I also are about to start cutting foam for my Q2 wing and canard.
I`m interested to see the replies, as I am about to use the LS1 profile with out the carbon-fibre spar I have been told that the GU is more efficient, but I don`t want to put vortex generators on the canard, starts looking like an unprofessional and ugly surface. I would like to know how much more efficient the GL profile is compared to the LS1.
I`m looking to use the blue foam rather than the old orange.
Ray
Melbourne
Aussi.he


--- In Q-LIST@..., Trevor Fernihough <spilligans@...> wrote:

Hi folks,
Two question for the group of folk who have built and are flying / have flown their Q's.

I have cut the foam previously (years go in fact) to build the Canard as a Q2. Subsequently I decided to go in the direction of the Tri-Q
and bought the kit including the new templates for the LS wing, carbon fibre spars and undercarriage. The undercarriage is now fitted to the fuselage. When looking to recut the foam for the canard, it is evident that the new profile just goes outside of the already cut foam, leaving me to have to get new foam blocks (no simple matter here in Australia).

First question: Listening in on your chit chat, leads me to believe that the GU is a more efficient wing than the LS canard, and that by installing vortex generators on the GU, I would have the more efficient canard without the contamination deterioration issue.

Have I interpreted the facts correctly in that regard ?

If so, then the second question is: To use the previously cut GU foam, is it simply a matter of squaring off the inside ends of the innermost cores and laminating the wing just exactly as though it were for the Q2 with the shear web etc just as per plan. This was obviously built to take landing loads and begs the question that if now not doing so, it could be / should be laid up with less cloth saving unnecessary weight ?

Any thoughts and advice greatly appreciated

Regards

Trevor



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