REFLECTOR:VG's on my XL results

[Rodney Brim]

Just to throw my results into the mix.
Placing the VGs on the wind and canard consistent with the factory templates
I got the following results:
1. Stall speed decreased 4kts
2. Cruise speed decreased 3kts
3. Control at approach speeds improved.
4. Nose drops on landing more abruptly when the lift finally gives away.
5. Lift on the canard was noticeably increased during cruise.
6. Decrease in take-off roll was 7% above what I got with the trailing edge
fences (from 15% up to 22% or thereabouts).

Modifications.  I took off one of each pair on the canard to decrease the
nose up pressure during flight, with not significant improvement in cruise
speed.
I eventually removed all of the VGs because the stall fences allowed me to
get into a short field (under 3,000') acceptably,
and I didn't want the cruise speed reduction.  If I flew out of short or
high fields all the time, I would add them back.  I was/am still looking for
the magical 200kt cruise speed, and mine typically gets a GPS speed of 185
kts.  By-the-way, changing from arm-pit scoops to top naca scoops did
nothing to improve my cruise speed either, although it certainly has given
me high climb-out temps (cruise temps are the same).

Rodney Brim,



-----Original Message-----
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
Behalf Of Chuck Jensen
Sent: Monday, December 08, 2003 9:01 AM
To: 'reflector@tvbf.org'
Subject: RE: REFLECTOR:VG's


And???

Chuck Jensen


Subject: RE: REFLECTOR:VG's


And finally, given all the earlier concern about reduced aileron
effectiveness at slow speeds, your photos makes one wonder about a row
of
VGs just ahead of the ailerons, ala Javelin?  Who will be the first to
test
this breakthru idea?

Chuck Jensen

Simon Aegerter has already done that.

Al

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