REFLECTOR:Belly NACA
Alexander Balic
reflector@tvbf.org
Tue, 22 Jul 2003 08:48:44 -0500
Chris,
it is at the hanger at the moment, but I would estimate that the opening is
approx. 1 1/2" x 14" and the length of the scoop from the foreword tip to
the inlet is about 28" and about another 18 or so behind to fair back into
the lower cowl- for me, I need to use it, because I can't cut into the skin
in the belly- gear bulkhead is down there with pulleys, plus the sump is
already sandwiched between the spar and the floor, so external is the way to
go for me, I would think that it would be a lot easier also, but a tad more
drag inducing......
Alex
PS, I'll try to get some pictures of it for you in the next day or so- just
feels like an ez bake oven in that hanger right now - the fan I have just
makes it into a convection oven........
-----Original Message-----
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
Behalf Of CBarber
Sent: Monday, July 21, 2003 10:43 PM
To: reflector@tvbf.org
Subject: RE: REFLECTOR:Belly NACA
Alex, Group
Is that "external belly NACA" a single scoop or a set of two like on the
top. I assume it does not extrude down so far as to be a big drag problem.
I don't know if two on the bottom or one is better/more efficient etc. I am
considering just making them out of the belly skin like they were done on
the top before VeloInc started supplying the premade ones. It does not seem
that difficult. By any chance do you have the dimension on the one for the
XL. Unless it is huge, it may be worth considering for my application.
Obviously I am in the preliminary planning/investigation phase. I just know
this will probably be easier now than later. And since I am trying it get
the cash to buy my wings, I gotta do something productive on the project
<g>. As always, thanks.
All the best,
Chris
Christopher Barber
Attorney and Counselor at Law
11930 S Sam Houston Pkwy E
Suite 103
Houston, Texas 77089-4755
281-464-LAWS (5297)
"Serving the needs of Senior Texans"
CBarber@TexasAttorney.net
www.TexasAttorney.net
-----Original Message-----
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
Behalf Of Alexander Balic
Sent: Saturday, July 19, 2003 9:33 PM
To: reflector@tvbf.org
Subject: RE: REFLECTOR:Belly NACA
Chris,
Velocity has an external belly mounted NACA that they supply with the XL
kits, I have one, and I will be using it for the radiator on my XLRG, it
mounts externally to the belly, and forms the inlet by raising the
surrounding area instead of lowering the skin, but the skin naturally
diverts from the air stream there anyway, so I suppose it works OK,, I will
have a radiator in the same place that you will, so I am going to install
the belly scoop so I don't have to route all of that air from the top. and
use the top 2 scoops for other cooling needs.
Alex
-----Original Message-----
From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
Behalf Of CBarber
Sent: Saturday, July 19, 2003 7:22 PM
To: Reflector@Tvbf.Org
Subject: REFLECTOR:Belly NACA
As y'all may know, I plan to use a Mazda Rotary on my SE fixed gear. With
the engine mount I already have, there is ample room to position a full size
radiator under the engine mount angled facing forward. Unlike the duel
NACA's that need to be split on top of the fuselage and go to each bank of
cylinder heads for a Lyc/Frank/Cont, I should only need one air source to
the radiator set up to provide adequate cooling. I have seen this done with
a NACA scoop installed on the bottom of a Cozy but the under the engine set
up on another Velo I saw had a "big ol' scoop hanging under the fuselage
(which is not my preference).
Do y'all see a problem with me doing this on my Velocity. I would appreciate
the groups input as to problems I may encounter or reasons this may be a
bone-head idea. My thoughts as to issues I need to address include:
1) Do NACA's work ok on the bottom of the plane? Yep, start with the
basics. I have read contradictory views on NACA's use. Some seem to love
them on their Velocity's, some don't.
2) I will need to cut out about 1.5 inches high, by 9-ish inches wide, hole
from the bottom of the "gear bulkhead" to fit the NACA scoop. I would
reinforce the missing material with some Triax. Should this reinforcement
be enough? Thoughts?
3) I will need to raise "sump tank" about 1.5 - 2 inches since the NACA
scoop will be where the sump sets. It seems easy enough to elevate the sump
and rest it on the top of the NACA scoop once it is installed and create a
solid pedestal for the sump to rest upon. Will the added height effect the
gravity flow from the main tanks? The pictures I have seen seem to indicate
this is a non issue as the main tank lines seem more than high enough to
accommodate a slightly elevated sump tank....but photo's can be deceiving.
4) Of course, before I decided on using the rotary, I already installed my
two top mounted NACA scoops on my SE. Does anyone have a use for
them....such a supplemental/primary cooling of something such as accessories
(alternator, potential turbocharger etc) or would I be better off closing
them back up. Also, if they were closed up, would the airspeed be
potentially increased. Also, I can't imagine a good way to duct the flow
from the top NACA's around the pipes and engine to underneath the engine and
mount to the bottom mounted radiator....thus necessitating this entire
question. The radiators can be set up in different ways, it is just under
the engine mount seems clearly the best.
5) Finally, I know I could just "build" the scoop into the bottom of the
fuselage, but I am inclined to just buy a pre-molded scoop from Velocity,
Inc. I know technically, there is a right NACA scoop and a left NACA scoop,
but on the two that came with my kit, I can see VERY little difference.
Anyway, the standard scoops are about 9 inches wide.....how wide are the
scoops on the XL and would the larger XL scoop prove a better choice.
Thanks for your input, considered opinions and time as to what I may be
missing and/or other thoughts.
All the best,
Chris
www.LoneStarVelocity.com
Christopher Barber
Attorney and Counselor at Law
11930 S Sam Houston Pkwy E
Suite 103
Houston, Texas 77089-4755
281-464-LAWS (5297)
"Serving the needs of Senior Texans"
CBarber@TexasAttorney.net
www.TexasAttorney.net
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