Re: Air Flow at canard - fuselage intersection LS1


Dave Richardson <dave@...>
 

(Sorry keyboard misfire on the last post.)



Here is a link to a Quickie photo.



http://members.shaw.ca/ghillsden/page5.html



The shape shown is a ramped channel cut into the side of the fuselage
with the thin end aft that contours over the canard and the thick end
inside the cowling. That contour example looks just like how the oil
flowed out of my cowling and over and above the canard area. If you
also look in the photo section of the Q-List you will see some Q2 fluid
dynamic images. The side shot shows the nice low pressure area above
the canard and aft of the firewall. If I understand this correctly,
having the ramp extend into that low pressure area will help draw the
air out of the cowling because it will be the path of least resistance.
If you also look at the fluid dynamic shot of the bottom of the Q2/xx
you'll see the high pressure area aft of the firewall in line with the
forward edge of the canard that most Q2/xx's try to dump their cooling
air into (the path of most resistance).



If you look at the Files section of the Q-List and open up the Side
Cooling folder Larry Koutz placed there you'll see what they did on the
Eagle 150 to get the air into the area above the canard as well as
Larry's manometer investigations of that area on his Q200.



Some of practical issues associated with actually implementing something
like this might be:



1) How big do they need to be?

2) Is there going to be any rudder pedal interference?

3) Keeping sufficient structure to keep that area strong and supporting
the firewall and canard attachments.

4) Possible streaks down the side of the plane from oil out of the
engine compartment

5) Getting the guts up to cut the fuselage and firewall



Dave Richardson

Tri-Q2 825DR 67 Hrs.







_____

From: Peter Harris [mailto:peterjfharris@...]
Sent: Wednesday, September 20, 2006 12:31 AM
To: Q-LIST@...
Subject: RE: [Q-LIST] Re: Air Flow at canard - fuselage intersection LS1



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
Oskar.

Peter

_____

From: Q-LIST@... <mailto:Q-LIST%40yahoogroups.com> [mailto:
Q-LIST@... <mailto:Q-LIST%40yahoogroups.com> ] On Behalf Of
Dave Richardson
Sent: Wednesday, 20 September 2006 1:19 AM
To: Q-LIST@... <mailto:Q-LIST%40yahoogroups.com>
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.

Join main@Q-List.groups.io to automatically receive all group messages.