Alex Fraser wrote:
> The catpack must catalyze the fuel. The wetted area must go up
> to match fuel rate. Wetted area is a surface. The fuel exists as
> a volume.
Ah ... no, theat's incorrect. The cat pack catalyzes the oxidizer -
HTP - not the fuel. The exhaust from the cat pack - pure oxygen at
1800 F - will ignite any hydrocarbon fuel on contact (therefor no
ignition system is needed).
> I don't think anyone has scaled up a silver screen catpak enough
> to really know how large they can be built. I think the larger they
> get the harder they will be to fabricate, that is harder out of
> proportion to size. What is the largest built to date? At what
> diameter of screen will you need to support it in the middle?
Ah ... wrong again - the Brits scaaled HTP/Kero engines to the point
where they put a 125 kg satellite into polar orbit using a three stage
vehicle. That sounds like a working solution.
> As for weight if you compare multi catpac single nozzle to
> multiple engines of the same thrust which would be lighter?
Lighter isn't the sole issue. Servicability is a top consideration.
Reliability is a top consideration. Performance of the overall vehicle
is a top consideration. There are lots of tradeoffs - it's not a
matter of size alone.
Michael
----------------------------------------------------------------------
Michael Wallis KF6SPF (408) 396-9037 [EMAIL PROTECTED]
President, Wallis International http://www.wallis.com
Coleman Orr:
"You either drift through life, or drive through it."
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