This is an actual V-2 rocket engine which has been cut away to show its workings.
The top or head contains 18 propellant injectors and the main alcohol (fuel) inlet.
Each of the 18 cup-shaped injectors has an inlet pipe at its top for liquid oxygen
(oxidizer). The injectors are arranged in a pattern of two concentric circles: 12
in the outer circle, six in the inner one.
A single inlet for alcohol extends from the center of the chamber top. Each injector
houses rows of nozzles, which atomized the propellants. Altogether, there are 2,160
nozzles for the liquid oxygen and 1,224 for the alcohol.
The combustion chamber itself is built with an inner and an outer wall. Alcohol was
circulated through the space between the two walls to cool the chamber. This technique,
called regenerative cooling, is still used in rocket engines today. Near the base of the
lower section of the chamber are six inlets through which the alcohol for engine cooling
entered. As an added measure of protection from the heat of the combustion, four
horizontal rows of holes were drilled in the inner wall of the chamber. When the engine
ran alcohol seeped out these holes to provide a protective film of cooling alcohol on the
engine nozzle.
