One possible reason it hasn't been done is that an engine management system
needs some actuators to manage if it's going to do any good. The
traditional rocket design with cooling passages feeding into an injector
doesn't lend itself well to putting any kind of flow regulating actuators
in that plumbing.
On Wed, Dec 9, 2015 at 6:29 PM, Monroe L. King Jr. <
monroe@xxxxxxxxxxxxxxxxxx> wrote:
Thanks for the PDF Lloyd, well yeah I look at it this way before we had
fuel injection we had carburetors. Engine management has made automotive
engines more efficient.
It seems to reason it can do the same for rocket engines.
Deep throttling is one area that it should help. The other aspect I'm
interested in is how much it could help the design process. Data
collection and analysis.
I'm working on a test stand for the turbopump and there are quite a few
data points and as I see it adding a few more, it just looks like an
engine management system. So why not just go all the way with it?
Turbocharger maps look like engine maps to me not much different than
timing maps or pressure temperature matrices. Pretty much all the same
to me. The combustion sensor is the only one I don't see in the current
array of sensors for a complete system.
I'm a pretty good tuner of engine management systems for race cars and I
understand them pretty well. Makes sense to me to apply it to rockets if
I can.
I am sure there are engine management systems for modern rockets there
just is not much talk about it. I could be wrong but I doubt it. It's
being done I'm pretty sure. Is it closed loop? That I'm not so sure of
but it would not surprise me.
-------- Original Message --------nor
Subject: [AR] Re: Closing the loop on rocket engines
From: Lloyd Droppers <ldroppers@xxxxxxxxx>
Date: Wed, December 09, 2015 4:34 pm
To: arocket@xxxxxxxxxxxxx
I have not heard of anyone using combustion sensors in a flight engine,
do I think that it would provide much value as most designs are eithernot
throttlable or already have an accurate measurement of propellant flowrate
in the feed system. What actionable information would an O2 sensorgather,
am I missing something?a
In the lab there are some extremely cool methods of measuring the
compounds,
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980201356.pdf is
bit old but it covers most of the basics of an H2/O2 systems in sectionchamber.
3.2, including direct measurement of gO2 using raman spectroscophy. But
these are primarily used for injector element experiments and design and
CFD code validation.
Lloyd
On Thu, Dec 10, 2015 at 3:33 AM, Monroe L. King Jr. <
monroe@xxxxxxxxxxxxxxxxxx> wrote:
I have not heard of using modern techniques such as those in the
automotive industry to control rocket engine combustion.
It occurs to me that if we want to have complete control over our
engines performance we need this same control over the combustion
process.
This would be especially useful for a preburnner system that
reintroduces the turbine gasses into the main rocket combustion
I'm wondering if anyone on arocket has heard of a combustion sensor
much like the O2 sensor in automotive use used to detect oxidizer/fuel
ratio in the exhaust gases?