Ken
Thanks for
the reply. Actually the scoop will
be supplying both the radiator and the oil cooler, so I may be a little small
by those figures. Ed had sent me
some CFM requirements earlier that seemed like I was in the ballpark maybe, but
I’m not sure how he calculated the CFM’s for the inlet area.
Steve
-----Original
Message-----
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net]On Behalf
Of kenpowell@comcast.net
Sent: Tuesday, July 13, 2004 5:40
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] New Scoop
Steve,
As another data point we had a pro cooling
system engineer who did some calculations for Mike Wills. Fred Morino
calculated that for 160 HP at 180 MPH (I think this was the speed) that we
(RV'ers) would need a rad intake of ~50 sq inches and an oil cooler intake of
~25 sq inches (does anyone still have Fred's results - I can't seem to find
where I filed this paper - I fear it is on a computer that I junked).
This always seemed a little large to me but you seem to be very close, so this
should be a good starting point for your tuning.
Ken Powell
--------------
Original message --------------
> Ed, and others -
>
> Attached are some photos of the new scoop I'm building to replace my old
new
> scoop. As you can see the new one actually has less intake area, but
> extends further in order to get outside of the boundary layer.
>
> I don't want the intake any larger than it has to be, but I want to make
> sure also that it is sufficient to allow for enough air flow. My old new
> scoop did improve cooling, but as I found out, it was only marginal.
>
> The new scoop, which is patterned after a P51 style scoop, not only gets
> outside of the boundary layer air, but also excludes it, with the dam that
> you see at the bottom. Well, actually it will be at the top, once it is
> mounted under the belly. It also gives me an expansion area once inside
the
> scoop.
>
> Using the program that Al sent me, the boundary area calculated out to
about
> 1.625-1.75 inches +/- depending on speed.
>
> The scoop intake measures 10.75" inside at the top (narrowest) and
14.75" at
> the widest point average = 12.75"
> Height of the inside of the scoop measures 4.25"
> This should equal about 54.18 sq in of area.
>
> The inside of the scoop sits exactly 2" from the bottom of the
fuselage, and
> overall height to the outside of the scoop is about 6.6" again,
measured
> from the fuselage bottom.
>
> I haven't glassed the scoop yet, other than on one side to help with
gluing
> it together.
>
> I am interested in any feedback concerning the size of the intake area.
>
> Regards,
>
> Steve Brooks
> Cozy MKIV N75CZ
> Turbo Rotary