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How can altitude not make a difference?
Springs are always relative devices. ALWAYS.
If you got a one inch hole with a spring that resists 10# of boost at sea level. The means that it can only resist 10psi DIFFERENCE.
At sea level (atmosphere ~14PSI) you go to MAP ~24PSI of boost, your ok. MAP 25 and the spring opens.
At 20K ft the spring will be open at over 14PSI MAP (atmosphere ~5PSI).
Big difference.
Now this example highlights extreme cases. It might be fine in a traditional home builders mission, perhaps at low altitudes. The reduced MAP at altitude might not matter to most people.
But altitude makes a difference in this device.
marc wrote:
Common in turbo normalized aircraft installations. Look at the T337P. Go
to RAM's website. Altitude makes no difference in this device, just
absolute manifold pressure.
Marc Wiese
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of John Slade
Sent: Tuesday, June 01, 2004 8:57 AM
To: Rotary motors in aircraft
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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