I should also mention it would run at a fuel-rich ratio, and we're looking
at using film cooling so that the steel can withstand the rigors of
operation. The 101 seems like a nice design to look back on for amateurs,
even if it wasn't a very high performance engine and wasn't very resilient.
I've seen it mentioned on AR a number of times that their walls burned
through easily...
On Tue, Oct 12, 2021 at 10:28 AM Jonathan Adams <jonadams2002@xxxxxxxxx>
wrote:
It's interesting you say that, as later on we (my team and I) are looking
at making a steel TCA using the same 4130 steel that the 101 used. Maybe
then we could take a good look at aluminum.
Jon
On Tue, Oct 12, 2021 at 9:23 AM roxanna Mason <rocketmaster.ken@xxxxxxxxx>
wrote:
The LR-101 Vernier engine ran off ratio,i.e. 1.8 so aluminum worked but
at 2.3 it would be under significantly higher heat flux,
Ken
On Mon, Oct 11, 2021 at 1:56 PM Henry Spencer <hspencer@xxxxxxxxxxxxx>
wrote:
On Tue, 12 Oct 2021, Jonathan Adams wrote:
The engine I'm working on now runs Jet-A and LOX at 350 psi and r =2.3
(when operating at its limit). For reasons relating to cost I've sofar
been looking at 6061-T6 aluminum, but I'm now wondering whether that's
the right choice... Can aluminum get the job done?
Yes, but. It's certainly been done; it's seen significant use -- mostly
with slightly cooler-burning propellant combinations, but if I recall
correctly, the LR-101 (Atlas vernier) injector is aluminum. The
downside:
it's unforgiving -- the cooling must be just right -- because it loses
strength so rapidly with even mild heating. With an aggressive oxidizer
like LOX, it can even ignite. Most likely not a good choice for early
experimental work.
Is there a grade of copper that is preferable for something like this?
C145, aka half-hard tellurium copper, seems to be what people like --
properties much the same as pure copper but a lot easier to machine.
Henry