GLOBAL KINETIC MODELING OF AVIATION FUEL FOULING IN COOLED REGIONS INA FLOWING SYSTEM

Jet fuel is used to cool military aircraft. Unfortunately, heated jet fuel reacts with dissolved oxygen to form products which foul fuel sys tem components. Two categories of surface deposits which form in the a utoxidative regime have been recently identified. The first forms in h eated regions as the fuel is oxidized. The second accumulates in coole d regions as certain compounds within the reacted fuel become insolubl e at reduced temperatures. This paper seeks to improve understanding o f fouling at reduced temperatures and to develop a global chemistry mo del that can be used in computational fluid dynamics codes. Experiment s were conducted in a flowing system using JP-8 fuel with different th ermal stability additives. Some thermal stability additives reduced fo uling in heated regions but were not as effective in cooled regions. T he deposition and oxidation measurements obtained for specific flow co nditions were used to calibrate a chemical kinetics model which uses g lobal reactions to simulate deposition. The calibrated model yielded r easonable predictions within the thermal and flow regimes considered.