Constructal law theory says that optimum cooling is probably fractal
channels, starting with large channels that divide into multiple smaller
channels and so on until you get down to the boundary layer thickness of
the fluid and then going back again the other way.
Doing that has lower pressure drop, so you can get better flow for any
given surface area; and you want high surface area, and it has *very* high
surface area. Of course you have to have the *right* scaling factor in your
fractal to give good performance.
On 16 September 2015 at 20:23, Dave McMillan <skyefire@xxxxxxxxxxxx> wrote:
On 9/16/2015 12:36 PM, Ben Brockert wrote:
I'm more curious if they're using standard channels or if they're
using a more modern design appropriate for a printed engine. I'm
always a bit frustrated when I see 3d printed engines with channels
that were designed for a milled chamber. At least spiral them enough
that differences in flow from channel to channel don't cause linear
hot spots and early failures.
That actually reminds me of something I've speculated about in the
past: if one assumes a "perfect" 3D-printing process for creating a regen
engine chamber/throat/nozzle, has anyone ever come up with an optimum
design for the cooling channels layout? While 3DP is hardly perfect, it
certainly does make previously-impossible complex interior geometries
suddenly a lot less impossible.
Hm... and it suddenly occurs to me that 3DP might make it possible to
iterate complex *injector* geometries much more rapidly than was previously
possible. Dunno if injectors might benefit from that as much as regen
channels, but anything that lowers the cost of trying different designs
can't hurt.
Going further afield... watching the various tech journals, it seems
we might not be so far from being able to print sensors, and their
"wiring," directly into the structure of of the engine. I have to imagine
that having a sensor "carpet" every few tens of millimeters throughout the
engine shell would be a boon to engine designers.
