Message-ID: <40E22880.9080604@nc.rr.com>
Date: Tue, 29 Jun 2004 22:42:08 -0400
From: Ernest Christley <echristley@nc.rr.com>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Temps finally down
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Ed Anderson wrote:
> 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

Plugging your fuselage's coordinates into a program like JavaFoil will 
give you some idea of how thick the boundary layer is where you have 
your intake.

-- 
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
   alleviated by information and experience."
                                   Veeduber