VGs are used to avoid separation and on the Lear Jet on the lower surface
on the horizontal for this same purpose, they are also used on the upper
surface of the wing to attuate the shock wave. I can see where they could
near the canopy if the flow is separated, rhis could be determined with
tuffs.
Jim
On Sun, 23 Jul 2006 07:00:29 +1000 (AUS Eastern Standard Time)
"StRaNgEdAyS" <stranged...@dodo.com.au> writes:
> I'm with Don.
> I'm thinking the previous owners were a little VG crazy. Given that
> the
> person who placed these VG's more than likely had no actual method
> applied
> to the placement, they are likely to be ineffective on any case.
> 0.02c
> Cheers.
> Pete.
>
> -------Original Message-------
>
> From: Donald Reid
> Date: 07/23/06 02:22:52
> To: m...@propilots.net; KRnet
> Subject: Re: KR> Vortex Generators
>
> At 08:45 AM 7/22/2006, you wrote:
> >My KR2 (built by others) was fitted with heaps of VGs under the
> >horizontal stab, on the fuselage prior to the rudder, on the
> landing
> >gear and in front of the canopy. A previous archive search
> suggested
> >that it lowers stall speed and if placed correctly has no speed
> >effect. There are none placed on the main wing (original
> aerofoil).
> >I don't understand why the previous owner wanted to lower the
> stall
> >speed of the horizontal stab, but not the main aerofoil...and why
> >the association with the rudder and canopy? Were they just VG
> crazy?
> >Any thoughts?
>
> The vortex generators upstream of the tail surfaces will/can
> improve
> control authority at low speed by keeping the airflow attached to
> the
> elevator or rudder when they are deflected. As for the gear,
> canopy,
> and other non wing-type surface, the only reason to put them there
> that I can think of is that the previous owner did not know what he
> was doing.
>
> Tripping the flow from laminar or turbulent to separated in a
> controlled manner (which is what a vortex generator does) can
> sometimes reduce drag, but only if it is done correctly. A vortex
> generator is not the proper way to do this. I suggest that those
> can
> be removed and you will not notice any difference.
>
>
>
> Don Reid - donreid "at" peoplepc.com
> Bumpass, Va
>
> Visit my web sites at:
>
> AeroFoil, a 2-D Airfoil Design And Analysis Computer Program:
> http://aerofoilengineering.com
>
> KR2XL construction: http://aerofoilengineering.com/KR/KR2XL.htm
> EAA Chapter 231: http://eaa231.org
> Ultralights: http://usua250.org
> VA EAA Regional Fly-in: http://vaeaa.org
>
>
>
>
> _______________________________________
> Search the KRnet Archives at
> http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html
>
> _______________________________________
> Search the KRnet Archives at
> http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html
>
>
