- Author
- Lockheed-California Company
- Title
- Investigation of Mechanisms of Potential Aircraft Fuel Tank Vent fires and Explosions Caused by Atmospheric Electricity. Final Report.
- Coporate
- Lockheed-California Co., Burbank
- Sponsor
- National Aeronautics and Space Administration, Washington, DC
- Report
- Final Report, May 31, 1963, 84 p.
- Contract
- CONTRACT-NASR-59
- Keywords
- aircraft fuel tanks | vents | explosions | atmospheric electricity | fuel vapors | lightning | blast waves | ignition | quenching
- Identifiers
- combustible environment; electrical environment; lightinig induced pressure waves; lightning simulation tests
- Abstract
- A study has been conducted to determine the important mechanisms involved in the ignition of fuel vapors issuing from a fuel tank vent under conditions of atmospheric electrical activity. The study included a literature review and experimental and analytical investigations of (a) the mixing of the fuel vent effluent with ambient air for three vent configurations at simulated flight conditions, (b) the electrical environment in the vicinity of an aircraft during lightning activity, including measurements of the far field pressures associated with a high energy discharge, (c) a study of ignition and flame propagation through channels smaller than the normal quenching distance using high energy spark sources, and (d) a study of simulated lightning discharges as to their capability of producing flames capable of propagating through a typical fuel vent with and without a flame arrester. The various separate programs and final correlating test sequence were performed. Profiles of constant observed fuel-air ratio were mapped using simulated vents installed in a wind tunnel. Characteristics of the electrical environment about an aircraft and the vent exit were derived from literature sources as well as actual probings. Pressure measurements associated with a high energy discharge were measured with pressure transducer and a Schleiran optical system. Flame propagation through normally quenching channels was studied by installing electrodes in a channel and supplying discharge energies of varying magnitudes. Results from these programs were correlated by installing a vent model in a simple wind tunnel and striking the model with simulated lightning discharges.