X-Mozilla-Keys:                                                                                 

 Fred could you please give us a sketch with radiuses of your choice of inlet

lip shape for the 200 MPH cruise case (RV series).

Fred wrote:

I have no special insight in this area and could only make rough guesses. I
will have a look at Miley's report (early 1980s) to see what he recommends.
Otherwise, I suggest going to the airport and looking at a late model (last 3
years or so) Piper inlet.  It was presumably done with some testing and since
one data point is worth one thousand sets of analysis, is far more valuable
than my guess work or theory.

 The Piper inlets and Lopresti inlets have sharper edges than I would have
presumed to be effective, but there is nothing like a good test to put your
preconceptions into the circular file.

Another suggestion: go to the Lopresti web site (I don't have it here,
suggest a search under LoPresti Speed Merchants) and look at Twin Commanche
cowl inlets. He has some good photos, and the inlets are about 6-7 inches in
diameter, so you can do a bit of scaling and reverse engineering.  (Basic
engineering premise: never invent when you can steal something proven to
work...)  Since he makes his living doing this stuff, it is probably better
tested and verified than anything else you can copy.

Fred, AKA as "technology thief"  (and proud of it)

Makes sure the inner countour is of airfoil shape.

Paul Lamar
 
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