Ian & Irene Beadle wrote:

Mike, a NACA scoop in the side of the cowl will function as an air exit not
an air inlet, as this is a low pressure area on a RV.
Ian RV6A

Mike Wills wrote:

Ian,

  There's thousands of RVs flying around with NACA vents in the fuse side
just aft of the cowl for cockpit ventilation. The RVs that I've flown in
with NACA vents in the side flowed plenty of air to cool cockpit occupants
(or ignition coils). In fact I think Chuck's RV uses this arrangement for
cockpit ventilation (I was surprised that his muffler is so effective that
there is more cockpit noise due to air coming in the vents than due to
engine noise; very quiet with the vents closed at cruise speed). What am I
missing? Low pressure on the side of the cowl but high pressure 12 inches
further aft?

  I would think even if the side of the cowl was a low pressure spot
(relative to say the front of the cowl) it would be a high pressure spot
relative to the inside of the cowl (which should be low pressure also if
its not pressurized by ram air).

  Sure wouldnt be the first time I made a wrong assumption (hope nobody is
keeping score). :-)

Mike Wills

I think you are missing the pressure inside the cowl Mike. Particularly
if it has cowl flaps that are closed.

Paul Lamar
 
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