Influent of inerting process of multi-bays central fuel tank for civil passenger airplane under various gas distributions

Based on the assumption of zero mass accumulation in the fuel tank and all bays, a mathematical model to automatically determine the flow direction and rate via the pressure difference was set up, and iterative steps were offered. Then, the mole concentration of the oxygen in the each bay related to volumetric tank exchange of ullage via the differential method was obtained. Adopting Boeing 747 central wing tank as the object of study, the calculating results of the models show highly accurate with the experimental data published on the foreign literature. The central fuel tank of an unnamed domestic passenger airplane was employed to study the inerting process influenced by 4 different configurations of the nitrogen-enriched air inlet port and 2 different gas distributions. The result reveals that the inering effect is the best to distribute the nitrogen-enriched air into all bays according to the volume average while it is the worst to solo distribute the nitrogen-enriched air into an outside bay. Moreover, it is better to emplace the inlet ports on the symmetrical bays than the asymmetrical bays.