This cut-away area shows the double-walled nature of the burner cups.
Fuel, delivered from the turbopump, enters the area
between the two walls comprising the thrust chamber via the six alcohol inlets near the thrust chamber's exit
plane. The fuel flows forward, providing regenerative cooling to the thrust
chamber walls. The forward end of the combustion chamber is comprised of three
walls, forming the upper and lower "head chambers" or fuel manifolds. When the
main fuel valve (tall grey cylinder at the center of the thrust chamber head
unit) opens, fuel flows from the lower fuel manifold through the main fuel
valve to the upper fuel manifold. There it fills the area between the two
walls of the burner cups and flows through the fuel
injectors, where it mixes with liquid oxygen, enters the combustion
chamber proper, and is burned.
Picture 2 of 2.