Can't argue with the 1st paragraph which is about as well as you can phrase and
articulate that point.
I'd cautiously agree with the 3rd with a few caveats - many caveats actually.
Few things to be mindful of (which you already know):
The systems that favour pumps the most are 1st stages where you need reasonable
chamber pressures to gather reasonable efficiency from your nozzles. The lower
the atmospheric pressure (outside of the nozzle) the less useful high chamber
pressures are, hence the lower you can maintain your general system pressures
for feeding and tankage allowing for lighter containment. We've all discussed
this on numerous occasions.
Also, what are the materials being considered for the pressure containment?
Are we automatically discounting the use of light weight composite structures -
if so, it needs to be noted. If not, then the bar is lifted in terms of what
level of crappiness of your pump can be before there's minimal performance
advantage from utilising them.
Of course, what's also of critical importance is the density of your
propellant with these decisions. Light fluffy propellants will nearly always
favour pumps but the picture is far more blurred for propellants at the other
end of the density spectrum.
Troy
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On
Behalf Of Ben Brockert
Sent: Monday, 14 December 2015 8:46 AM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Hydrogen and oxygen used as pressurizing gasses
On Fri, Dec 11, 2015 at 7:02 PM, William Claybaugh <wclaybaugh2@xxxxxxxxx>
wrote:
Simple systems tend to be lower cost and higher reliability....