Vaporization of JP-8 Jet Fuel in a Simulated Aircraft Fuel Tank ...

7.0 CONCLUSIONS AND RECOMMENDATIONS
The experimentation performed was successful in measuring ullage vapor concentration
in a simulated aircraft fuel tank exposed to varying ambient conditions. A large set of
data was collected that included fuel vaporization testing at constant ambient pressure
and temperature, constant reduced ambient pressure, and flight profile tests with varying
ambient conditions appropriate to in-flight aircraft fuel tank conditions. The data was
useful in validating fuel vaporization model calculations from a pre-existing model. The
model calculations of ullage gas temperature and vapor concentration proved to be in
good agreement with experimentally measured data. The model was very useful in
describing the transport processes occurring within the tank and evaluating the
flammability in the experimental fuel tank. The flammability assessments indicated that
Le Chatelier’s rule was more conservative than the FAR rule, and that from a safety
perspective the FAR rule should be used in differentiating between safe, non-flammable
conditions and dangerously flammable conditions. The data generated has proven
successful in validating a model and can be used for further validation work.
Further detailed experimental data on JP-8 flammability limits is required for
further model validation, as well as laboratory testing in full sized aircraft fuel tanks and
possibly testing from a fully instrumented fuel tank in an in-flight aircraft. Actual fuel
tank testing would present several complications. Aircraft center wing tanks are divided
into several different compartments that are connected via small openings in the
partitions. This will complicate the internal flow field and possibly cause ullage gas
stratification between the compartments. Also, it was seen in this work that the model
calculations were heavily dependent upon the input temperatures; therefore accurate
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