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Message
John, similar to a radiator cap, the POV capacity
is rated assuming differential pressure. In other words, the rating
assumes there is 14.7 psi "helping" the spring keep the lid on. Going up
in altitude will, of course, reduce that assist as the ambient pressure
decreases. This means that if will probably open at less boost than you
set it for on the ground which means it will likely "pop" open at less
boost pressure at altitude. And as Rusty indicated, if you set it so you
get your max boost at altitude, then it will likely not release until even
higher (harmful?) boost pressures at sea level.
Ed
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
Sent: Tuesday, June 01, 2004 9:57
AM
Subject: [FlyRotary] Re: Pop off
I've
been thinking about the POV, and wondering how it'll behave at
altitude.
If
the air is pushing against a spring, perhaps the ambient pressure behind the
spring wont make much difference. Has anyone tested the behavior of a POV at
altitude. Seems to me that it would hold back pressure, even in a
vacuum.
John
(popping off to the hangar to remove cowl and investigate the last
flight)
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