Preliminary results of turbojet-engine altitude-starting investigation

A spark energy of 2.13 joules per spark at 1 spark per second produced ignition to an altitude of 50,000 feet at a flight Mach number of 0.6. The minimum power requirements for ignition were obtained from a combination of low spark repetition rates and high spark energy. The altitude-ignition limit was also increased by increasing spark-gap immersion, fuel temperature, inlet-air temperature, and fuel volatility, and by decreasing flight Mach number. The maximum altitude at which flame propagation was accomplished from combusters with spark plugs to combusters without spark plugs to combustors without spark plugs was increased about 5000 feet by increasing fuel volatility

Effect of fuel volatility on altitude starting limits of a turbojet engine

The effect of fuel volatility on altitude starting limits of an axial-flow-compressor-type turbojet engine was investigated using fuels with Reid vapor pressures of 1.1 and 5.4 pounds per square inch. At flight Mach numbers from 0.40 to 0.85, the AN-F-58 fuel allowed consistent windmilling at altitudes 2000 to 8000 feet higher than was obtained with the 1.1-pound Reid vapor pressure fuel. At a flight Mach number of 0.25, ignition could not be established at any altitude with the lower-volatility fuel

Preliminary Results of British Nene II Engine Altitude-Chamber Performance Investigation. I - Altitude Performance Using Standard 18.75-Inch-Diameter Jet Nozzle

An investigation is being conducted to determine the altitude performance characteristics of the British Nene II engine and its components. The present paper presents the preliminary results obtained using a standard jet nozzle. The test results presented are for conditions simulating altitudes from sea level to 60,000 feet and ram pressure ratios from 1.0 to 2.3. These ram pressure ratios correspond to flight Mach numbers between zero and 1.16 assuming a 100 percent ram recovery