Inerting of a Vented Aircraft Fuel Tank Test Article with Nitrogen-Enriched Air
Abstract
This report documents a series of experiments designed to determine the quantity and purity of nitrogen-enriched air (NEA) required to inert a vented aircraft fuel tank. NEA, generated by a hollow fiber membrane gas separation system, was used to inert a laboratory fuel tank with a single vent on top designed to simulate a transport category airplane fuel tank, The tank ullage space could be heated as well as cooled and fuel could be heated in the bottom of the fuel tank to provide varying hydrocarbon concentrations within the ullage space. Several inerting runs were performed with varying NEA gas purities and flow rates. The data was nondimensionalized in terms of NEA purity, volume flow rate, and fuel tank size to provide one universal inerting curve. Changing temperatures and hydrocarbon concentrations appear to have little effect on the amount and purity of NEA needed to inert the test specimen. A model of ullage washing developed by the Federal Aviation Adiministration Chief Scientific and Technical Advisor for fuel systems design, based on the volume exchange of gases of different concentrations, was compared with data obtained from the test article. Also, an exact solution based on uniform and instantaneous mixing was derived and compared with the test data. Both the model and exact solution showed good agreement in both trend and magnitude with the data obtained during the testing.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2001
- Accession Number
- ADA396168
Entities
People
- Michael B Burns
- William M. Cavage