Another view of 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 flows between the two
walls of the burner cups, flowing through the fuel
injectors, where it mixes with liquid oxygen, the mixture enters the
combustion chamber proper, and is burned.
At forward-center of the burner cup is the oxygen