Well, to a point. Like everything in life, you need a balance. Any performance
outcome that’ll be under your propellant combination’s c* or c*/g (in Isp terms
- ~165sec for this combination say) must have sub optimal mixing unless you
have a gaping hole in your chamber. Nobody should expect to hit optimal mixing
in the early days of development, but … dunno… if the mixing is too far out of
whack, does that not potentially expose the chamber to potential damage or hard
moments?
Troy
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Randall Clague
Sent: Tuesday, 13 September 2016 12:37 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: LOX / IPA P&ID
If it works at all, it probably delivers 100 seconds or more. Fine. My point
is, forget about that. One step at a time. Premature optimization is the
bloodsworn enemy of success. Step two is Make It Work, success is defined as
supersonic flow. THEN, and only then, focus on the numbers.
-R
On Monday, September 12, 2016, Jonathan Goff <jongoff@xxxxxxxxx
<mailto:jongoff@xxxxxxxxx> > wrote:
Randall,
While I agree with the general sentiment that getting something that fires
reliably and safely comes first, I think you'd have to try hard to get LOX/IPA
rocket that only delivered 100s Isp, even on a first try.
Jon
On Sep 12, 2016 4:28 PM, "Randall Clague" <rclague@xxxxxxxxx
<javascript:_e(%7B%7D,'cvml','rclague@xxxxxxxxx');> > wrote:
242 seconds is ambitious for a first effort.
First make it safe. Forget about Isp, your goal is making fire without making
shrapnel.
Then make it work. Forget about Isp, your goal is making supersonic flow
without making shrapnel.
Then make it work better. You probably hit 100 seconds in step two. Try to hit
200 seconds, but remember, Reliability Is More Important Than Performance.
-R
On Monday, September 12, 2016, Dillon Wessing <dillonwessing@xxxxxxxxx
<javascript:_e(%7B%7D,'cvml','dillonwessing@xxxxxxxxx');> > wrote:
Hi all. I am the lead of the USC Liquid Propulsion Lab. We’re developing a LOX
/ IPA engine and wanted some input/advice on our ground testing P&ID.
Just some general specs for the engine. 10 kN of thrust. Total mass flow 4.2
kg/s (fuel: 1.91 kg/s, ox: 2.29 kg/s). Chamber pressure 350 psi. Pressure going
into the injector 437. 5 psi.
We are having channels milled into our combustion chamber for regen cooling
with the IPA and will have a separate reg for the ox since the IPA will have
higher pressure drops. Please comment on the validity of this design and any
concerns that we should keep in mind.
Best,
Dillon Wessing
