Intuitively I would say that using LOx as a coolant can help with reaching
your propellants maximum theoretical heat capacity prior to ignition and in
some cases, your fuel alone might not be sufficient for cooling. The case
of the SSME/RS-25 injector assembly also came to mind, the LOx injector
piping was wrapped in warm/hot Hydrogen in order to warm up the LOx to
catalyze combustion (maybe not exactly the right wording). Another thought
that came to mind is LOx cooling might be advantageous in something like an
aerospike, not to go down this rabbit hole too much but there might not be
enough fuel flow to cool both the outer chamber wall and the inner spike
but that thought does not have much analysis behind it.
On Mon, Oct 19, 2020 at 5:50 PM ken mason <laserpro1234@xxxxxxxxx> wrote:
Why would you want to use LOx anyway,is your fuel even less satisfactory?
It's low heat capacity and low critical temp, leading tio two phase flow,
are several reasons against it's use as a regen coolant.
K
On Mon, Oct 19, 2020 at 5:33 PM Yucca Works <pyropickle1@xxxxxxxxx> wrote:
I want to get this group's thoughts, experience stories, and
possibly advice on regenerative cooling with liquid oxygen at the small
scale (<500lbf)? I have read the public NASA paper that concerns cracking
in the chamber and local hotspots and have looked into (what little has
been released to the public) Launcher's work with their small 3d printed
copper engines. On paper at least, it seems like one can get away with
cooling from the throat up (the entirety of the combustion chamber). This
is just curiosity-sparked research, nothing beyond that yet.