I was also going to suggest ablative or film cooling.
Ben's recommendations are great.
On Mon, Aug 10, 2020 at 6:32 AM Ben Brockert <wikkit@xxxxxxxxx> wrote:
For an amateur project there's a lot to be said for not doing regen,
and starting with a film cooled stainless engine. Design it so that an
orifice can be put before the film cooling manifold, so that you can
do the first tests with the film cooling full open and throttle it
back until you hit the temperatures you're looking for. Or (better)
plan to iterate, so spend some time making the injector manufacturable
and recognize that the third engine will be the one that works. Even
if the film cooling isn't working right you can do short runs in heat
sink mode and gather useful data on injector and cooling performance.
The chamber and nozzle can be rolled and welded. Build it heavy. An
impinging injector can be made on a 2.5 axis mill with some fixturing,
it doesn't require 5 axis CNC, though if you have it you can use it. A
pintle can be mostly made on a lathe. Would be interesting to see how
simple someone could make a micro coaxial.
It is definitely easier if you use a propellant combination where the
fuel volume is proportionally larger, like lox/alcohol rather than
lox/kerosene. That also means that when you go to make tanks they can
be equal volume. To make it even easier from a cooling perspective you
can take the guidance of the historical Germans and the current
Copenhagenites and add some water to the alcohol. It reduces the
temperatures faster than it reduces the performance.
You're not going to make orbit on it, but you can certainly get to space.
On Mon, Aug 10, 2020 at 8:22 AM Jonathan Adams <jonadams2002@xxxxxxxxx>
wrote:
the thrust chamber for a small liquid-propellant rocket engine?
How would one, particularly on an amateur scale go about manufacturing
manufacture, as a longer combustion chamber would be difficult to machine
I was wondering this because it seems like a difficult component to
via CNC turning or a similar process due to complications with removing
shrapnel from inside the chamber as it is being machined.