Re: Air Flow at canard - fuselage intersection LS1

Peter Harris <peterjfharris@...>

Dave, I made gills for cooling the Norton and have kept them for the Jabiru
3300 installation. I was not aware of Burt's work. I cut "D" shaped panels
from the rear side cowl one each side and glassed the "D" reversed inside
the cowl to make inverted "gills". I think they produce no drag and located
in this low pressure area they work well. But I have retained the shroud and
tunnel underneath. When the shroud is closed I get a cruise CHT of 239degF
when ambient is about 77degF. These gills show up in the pics file for VHONQ



From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of
Dave Richardson
Sent: Wednesday, 20 September 2006 1:19 AM
To: Q-LIST@...
Subject: RE: [Q-LIST] Re: Air Flow at canard - fuselage intersection LS1

Hi Jim,

I had similar results in some "unscheduled" oil flow tests on my Tri-Q2
with an LS1. The specific point I saw was the arched clean area about
4-5 inches above the canard / fuselage intersection. I always wondered
what the air was doing right in the contour between the canard and
fuselage. Some had suggested that it was compressing the air there
which would cause drag and less of a V shape and more of an L shape
there would help. That is a compound low pressure area from the canard
shape as well as the fuselage shape. In fact, it is low enough to suck
loose oil from inside the cowling (hence my "tests"). You know I think
Burt and co. really had it right on the Quickie by putting the major
cowling exit air out over the canard through those gills. On the Q2/xx
we try to dump the cooling air out into a high pressure area under the
fuselage and we have these two nice low pressure areas. I'm sure there
are other considerations, though. The Eagle 150 uses this area for
their cooling air exit.

Anyway, thanks for sharing the photos.

Dave Richardson

Tri-Q2 825DR 69 hrs.

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