We never used film cooling at XCOR, and had 97% or more cstar with
LOX-kerosene at 2.6 O:F, no mixture ratio compromises. I've never
understood why everyone else seems to struggle with efficiency vs stability
vs cooling- they all pull together in unison. I just applied design rules
published fifty years ago.
On Mon, Oct 11, 2021, 3:20 AM roxanna Mason <rocketmaster.ken@xxxxxxxxx>
wrote:
No, it's not that difficult to build high reliability long lived biprops,
the trick is to do it with high efficiency, c* that is, not off ratio
and/or lots of film cooling as was done with that Spectre RATO engine which
BTW was derived from an earlier Aerojet RATO rocket system using nitric
acid oxidizer with variations of fuels.
Thanks Henry for mentioning Bruno, I lost all my data earlier this year to
a hard drive crash and Bruno's info was one of the casualties. I had ~ 40
pics of that Spectre system with subassemblIes of the TCA showing the
cooling jacket construction which was simple enough for amature use.
If anybody has that link of Bruno's I'd love to get it back into my
archives.
Thanks,
Ken
On Sun, Oct 10, 2021 at 9:22 PM Henry Spencer <hspencer@xxxxxxxxxxxxx>
wrote:
On Sun, 10 Oct 2021, roxanna Mason wrote:
you get something as flaky and short-lived as a typical rocket engine
Enter SpaceX, particularly their Raptor which is claiming 100 flights.
SpaceX was by no means the first to build reliable, long-lived rocket
engines; citing this as another Miracle Of St. Elon :-) is silly. See,
for example, the attached (posted by Bruno a few years ago) -- note
position of test crew in relation to 1950s rocket engine. If you want
something more recent, see assorted videos of XCOR tests.
It's not magic, it just requires different design priorities and a
different test program -- much more like those of a normal jet engine,
meant for a manned aircraft.
Henry