Cold Ambient Temperature Effects on Heated Fuel Tank Vapor Concentrations

Details

• Creators:
  Summer, Steven M.
• Corporate Creators:
  United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center
• Corporate Contributors:
  United States. Department of Transportation. Federal Aviation Administration. Office of Aviation Research
• Subject/TRT Terms:
  Aircraft Fuels Altitude Atmospheric Temperature Flammability Fuel Tanks High Altitude Low Altitude Vapors
• Publication/ Report Number:
  DOT/FAA/AR-TN99/93
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Technical Notes
• Corporate Publisher:
  United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center
• Abstract:
  Experiments were conducted within a simulated aircraft center wing fuel tank (CWT) to qualitatively analyze the effects of decreased ambient temperatures, such as might occur at increased altitudes, on the vapor concentrations found in a typical CWT ullage. A small quantity of fuel in the CWT test article was heated to 125°F for two hours, corresponding to a temperature of approximately 10°F above the flashpoint of the fuel. The tests were conducted at sea level (14.7 psia), however, the wall temperature of the tank was cooled to a temperature corresponding to a given altitude.
  
  From these tests, it was determined that the ambient temperature does indeed have a significant effect on the vapor concentrations formed in the fuel tank ullage at small fuel mass loadings. When allowed to cool naturally to the room's ambient temperature (-75°F), the fuel-air ratio decreased at an average rate of 1.07 x 10-5 min-1 for the low-altitude test, it decreased at an average rate of 7 .50 x 10-5 min, and for intermediate- and high-altitude scenarios, it decreased at an average rate of 1.58 x 10-4 min-1 and 2.08 x 10-4 min-1, respectively. Thus, as the ambient temperature is decreased, the rate of decrease in the fuel-air ratio increases.
  
  
• Format:
  PDF
• Collection(s):
  FAA William J. Hughes Technical Center for Advanced Aerospace
• Main Document Checksum:
  urn:sha-512:3b3fba1026ad006f76563cc98e1902a9c456020a3cb9343c156ac2b7f7080d058dca9a748f69292ac8dd5ac8a94b245e46f174cbbd2d0c3a99de5c50504129c1
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/90173/dot_90173_DS1.pdf
• File Type:
  [PDF - 527.67 KB ]