Pressure points above the fuselage in cruise speed

[ron sterba]

Does anybody have a map of the HIGH & LOW pressure gradients every half foot over the RV fuselages from the nose to the tail. The reason I ask is because I'm wanting to install my upper cowl with those quarter turn fasteners as opposed to the hinge style. My friend says that theres plenty of warm air that escapes the rear top cowling to provide a defroster for the windsheild. Would like your thoughts on the subject. Live in Oregon..

Ron

[Wayne Gillispie]

There is plenty of higher pressure air under the cowl wanting to escape. What escaped through my top rear hinge area was not enough heat to keep winshield from fogging up two weeks ago. There was about 1/2" dry snow at the airport. I preheated engine and cabin for the family(4 of us). After a five minute taxi/runup behind a 172(yep, was not the first to make tracks), then takeoff at 21F, all windows started fogging up on initial climbout. Thank goodness for two 80 mm 12 volt computer fans(defrosters). It was our first time using them and they worked great. My side windows cleared five minutes later as cabin heat is way more than enough. Kept a microfiber cloth handy just in case.

[Bruce]

Ron,

Did not work on plane this weekend.

I hope the seal is not leaking that bad or you are
losing some valueable pressure in the cowl.

My .05 worth