NACA Research Memorandums

An altitude-test-chamber investigation of a 28-inch-diameter ram-jet engine at a simulated flight Mach number of approximately 2.0 for altitudes of 40,000 to 50,000 feet was conducted at the NACA Lewis laboratory. Three different flame holders, varying in the number and size of the annular gutters, in conjunction with several fuel-injection systems were investigated. The combustion efficiency for the flame-holder fuel-injection system that provided the best over-all operational fuel-air-ratio range (0.03 to 0.075) was over 0.9 at a fuel-air ratio of about 0.065 for the altitude range investigated