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Date: Fri, 29 Feb 2008 16:42:23 -0500
From: Ernest Christley <echristley@nc.rr.com>
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Subject: Re: [FlyRotary] Re: New (old) guy on list
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Greg Ward wrote:
> MessageI would also be really interested in seeing some others cooling solutions.  I was told that 40% of the Lancair's drag is in the cooling drag, and I am contemplating a belly scoop A la' P-51, and have created controversy about how much that configuration will add to the drag factor.  In other words, I might get great cooling at a slower speed?  Supposedly the P-51 configuration creates enough thrust to overcome around 90% of the drag created, but I would like to confirm that before I go through the process of designing and building the damn thing.......(:-)  Call me lazy...
> Greg Ward
> 20B Lancair in Progress
>   
My survey of the studies and anecdotal evidence that I could find, 
indicate fairly conclusively that radiators inside the engine cowl is 
about the worst possible option when considering cooling drag.  However, 
for many it is the only option, and for most it is by far the easiest 
option.  The planform of my project is completely different than most, 
giving me a relatively easy option of installing the rads and ducting 
within the wing's 18" thick airfoil.  I'm not even fantasizing that I 
will wind up with net positive thrust, just confident that it won't be 
quite so negative.

With a conventional planform, how would you seperate the hot tube from 
the fleshy parts of the airplane?  Long hose runs will be heavy, 
especially if you use 1" hose to keep a reasonable flow.  And the 
placement of the weight could possibly play havoc with your W&B (it was 
actually a slight improvement for my situation).

One thing is very clear, though.  If you can make it work, it'll be one 
of the sweetest looking Lancairs on any field it visits.