Steve, the boundary layer has "no velocity" (less velocity) thus less mass
flow of air thru your rad.  The boundary layer is the thin (or thicker if
farther aft) layer of air close to the skin that is being slowed by skin
friction, etc.

David

----- Original Message -----
From: "Steve Brooks" <steve@tsisp.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Wednesday, June 30, 2004 6:52 AM
Subject: [FlyRotary] Re: Temps finally down


> Ed,
> I would like to have more information on the reason for keeping the
boundary
> layer air out.  My current scoop is open, and lets in both.  If the
boundary
> layer air needs to be excluded, then my next scoop will have to be like
the
> P51 scoop which does exclude it.  I never really understood why.
>
> Looks like I may have to have another look at Bulents' scoop.  His is made
> like the P51.
>
> Steve
>
>  -----Original Message-----
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]  On
> Behalf Of Ed Anderson
> Sent: Tuesday, June 29, 2004 7:56 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: Temps finally down
>
> Sounds like you are closing on the solution, Steve, congratulations.  Its
> always nice when you get to the point where you can fly without one eye on
> the temps.
>
> The boundary layer (particularly with coolers to the rear of an airframe)
> appears to play a big role.  The layer increases in depth as you go
rearward
> and it creates havoc with the operation of cooling ducts and diffusers.
One
> article I read indicated the American P-51 and German fighter designers
> figured out the significance of keeping the boundary layer out of the
> cooling ducts whereas the British supposedly continued to be plagued with
> cooling problems with the Spitfires due to their cooling inlets being
partly
> in the boundary layer.  FWIW
>
> Keep us apprised
>
> Ed
>
> Ed Anderson
> RV-6A N494BW Rotary Powered
> Matthews, NC
> ----- Original Message -----
> From: "Steve Brooks" <steve@tsisp.com>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Tuesday, June 29, 2004 6:37 PM
> Subject: [FlyRotary] Temps finally down
>
>
> > I made my eight flight today, and I'm happy to report that my inlet
scoop
> > augmentation on the Cozy did the trick.
> > I flew only about 1/2 hour because I had some other work that I wanted
to
> do
> > on it, but the temperatures ran at 190 coolant, and 200 oil.
> > I climbed up a couple thousand feet, and instead of  throttling back and
> > watching my temperatures come back down from 210/220, I wasn't quite up
to
> a
> > stabilized temperature yet.  That was a big change.  I pulled power back
> to
> > what I had been running previously, and the temperatures stayed the
same,
> > maybe dropped a little.  I then throttled up to zero boost, and the
> > temperatures held.  YEAH !!!!!  They used to climb up with the throttle.
> > On the decent to landing, I thought that I would have to chip the ice
off
> of
> > the engine.  Coolant dropped almost off the gauge to about 140, and oil
> down
> > to 160.  Actually when I touched down, they were even lower than that.
> >
> > Now that I know that I can cool it, I'm going to make another scoop,
> > narrower on the sides, but a little taller (actually lower) to get a
> little
> > further outside the boundary layer.  The next scoop will have a smaller
> > inlet area compared to the current one.
> >
> > Steve Brooks
> > Cozy MKIV N75CZ
> > Turbo Rotary
> >
> >
> >
> >
> > >>  Homepage:  http://www.flyrotary.com/
> > >>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
> >
>
>
>
> >>  Homepage:  http://www.flyrotary.com/
> >>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
>
>
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