Promoters for Low Temperature Spray Ignition

Some older turbojet engines have had trouble with engine start at low ambient temperatures since the change in logistic fuel from JP-4 to JP-8. This engine starting difficulty can seriously affect force readiness in time critical operations. Our analysisindicates that this lightoff problem is fundamentally related to the fact that JP-8 fuel sprays have a much larger ignition energy requirement and quenching distance than JP-4 sprays. While mechanical changes to the TF33 engine could be made to obtainJP-4-like light-off performance with JP-8, this option is likely to be very expensive. A far less expensive option would be to use an ignition-promoting fuel additive during the winter months. TDA therefore proposes to use an existing,temperature-controlled spray ignition apparatus to investigate several classes of ignition-promoting fuel additives that hold promise to improve low temperature spray ignition while maintaining compliance with the JP-8 fuel specification.Success in thisproject would restore JP-4-like engine light-off performance to the B-52 in winter while conforming with the JP-8 fuel specification.