Thermal Decomposition of Aircraft Fuel

A test program has been conducted to determine the thermal stability and heat transfer characteristics of JP-5 and several other kerosene-type fuels which vary in composition and tendency to form deposits. Tests were conducted in small-diameter, resistively heated tubes at typical aircraft engine operating conditions. A detailed mapping of the thermal decomposition characteristics of JP-5 was performed to evaluate the importance of key environmental factors—such as temperature, pressure, flowrate, and test duration—and to establish a data base for estimating the relative performance of new fuels. Tests were conducted over the temperature range 425 to 870 K for durations up to 32 hr. Fuel deposition rates varied among fuels, and the relationship between the “breakpoint temperature” (determined according to ASTM D3241) and the rate of fuel deposition was investigated.