Hydrogen Content as a Measure of the Combustion Performance of Hydrocarbon Fuels

Previous work by various investigators has shown that the hydrogen content of a hydrocarbon jet fuel is the primary variable affecting the combustion performance of the fuel; i.e. the amount of heat radiated during the combustion of the fuel within the jet engine combustor. The results of statistical correlations of fuel data are presented wherein the hydrogen content of fuels is correlated with other fuel combustion measurements including smoke point, luminometer number, and net heat of combustion. Also, the hydrogen content of fuel is correlated with the specific gravity and aniline point measurements. The report concludes that the fuels' hydrogen content can be calculated with sufficient accuracy to eliminate the need for measuring smoke points, luminometer numbers, and net heat of combustion. For conventional jet fuels (JP-4, JP-5, JP-8, Jet A, Jet A-1, and Jet B) a minimum allowable hydrogen content of 13.5% by weight is recommended.