Book Description

The combustion performance of potential hydrocarbon fuels for supersonic aircraft jet engines was evaluated in a J-79 engine combustor. The combustor test conditions simulated full-scale engine operation at high altit des and supersonic speeds. As the inlet air pressure decreased, the combustion efficienc decreased. Differences in combustion efficiency were noted between 8 fuels at the various operating c n iti ns. A comparison of the fuel flow requirement for a constant urner temperature rise (thrust) at two test conditions indicated lowest fuel flow on a weight basis for a paraffinic fuel and a production type JP-6 fuel; lowest fuel flow on a volume basis was indicated for a naphthenic fuel and isopropylbicyclohexyl. At a more severe operating condition the isopropylbicyclohexyl indicated a low fuel flow requirement on both a weight and volume basis. The effect of fuel preheat on combustion efficiency was negligible. Combustor liner temperat re ere not affected appreciably by fuel differences. The carbon deposits were very light for all fuels. The fuels with the higher ASTM initial and 10% boiling points had higher ignition requirements at simulated altitude relight test conditions. (Author).