Chapter VI Chemical Aspects of Thermal Stability

Abstract

From the initial observation that thermal oxidation stability of aviation turbine fuels could induce problems in the fuel system, it was realized that the difficulties varied from fuel to fuel. For instance, flight performance in the F100C aircraft operating at the same test conditions varied considerably for five different fuels [1]. After 100-h tests, the decrease in fuel flow into the combustor varied from 2.44 to 18.44%, a 7.5-fold range in behavior. Figure 6 of Chapter V also illustrates the wide response of jet fuels to thermal oxidative stress [2]. In this figure, the deterioration in heat transfer coefficient for three Jet A-1 fuels is shown as a function of fuel outlet temperature from the Shell Research STHTR. At a low fuel-out temperature (210°C), one fuel effects a 25 times greater change in heat transfer than another fuel, but at a fuel-out temperature of 240°C the three fuels exhibit a similar effect on heat transfer.