Date: March 30, 1953 Creator: Zettle, Eugene V Description: The
design principle of injecting liquid fuel at more than one axial
station in an annual turbojet combustor was investigated. Fuel
was injected into the combustor as much as 5 inches downstream
of the primary fuel injectors. Many fuel-injection
configurations were examined and the performance results are
presented for 11 configurations that best demonstrate the trends
in performance obtained. The performance investigations were
made at a constant combustor-inlet pressure of 15 inches of
mercury absolute and at air flows up to 70 percent higher than
values typical of current design practice. At these higher air
flows, staging the fuel introduction improved the combustion
efficiency considerably over that obtained in the combustor when
no fuel staging was employed. At air flows currently encountered
in turbojet engines, fuel staging was of minor value. Radial
temperature distribution seemed relatively unaffected by the
location of fuel-injection stati