Russell Kent wrote:

Russell Kent wrote:

I think that anyone who thinks maintaining SL pressure at FL30 (sic) is

not only

doable but also a good design goal is possibly in for a rude discovery.

Be wary...

Bill Jepson responded:

Russell, I want to mention something, all arguments about the use of

carbon fiber

aside. This guy is NOT, REPEAT NOT, a fly-by-night shyster. He is a very
knowledgeable fabricator. His day job is to build cars that go faster on

the ground

than many of our aircraft will go VNE! If he believes he can maintain SL

to FL30 I

wouldn't bet against him, however unlikely.

I make no claims about his skills as a fabricator.  I was merely pointing

out that

the likelihood of maintaining SL pressure at "FL30" (that's what he wrote;

I assume

he meant FL300 or 30,000 MSL) is exceedingly small.  Run the numbers.

There's a 10

psi pressure differential.  For a 36" x 18" windscreen, there's roughly

6,500 lbs of

force trying to separate it from the airframe.  It's even worse for the

door.

And by the way, now that he's sucked 10 psi @ ?? cfm out of the turbo to

pressurize

the cabin, how much is left to turbocharge the engine?

The simplistic test: if it were a good thing to do, why aren't Boeing and

Airbus

doing it?

Russell Kent

You are first in line Russell. I hope you can spare the time.

Paul Lamar

-"Decker, Michael" wrote:

Have you taken a look at the tensile modulus for polycarbonate lately?  It's
not that hard to  design bubble shapes that spread loads in tension of this
type.  The abuttments are a little bit harder but not impossible.

Would I stake my life on this, (as will the test pilot), NO.

I do agree on the point that scavenged turbo is a poor source of
pressurization.

My major experience of this type is in vacuum chambers, not pressure.  I
like this subject, though, and invite those who've been there and done that
to opine.

Mike Decker

Don't keep us in the dark Mike. What is it? Most people use acrylic
windshields. I tried to buy a Lexan for my Cruiser and nobody
wanted to do it.

Paul Lamar
 
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