Effect of Airflow and Measurement Method on the Heat Release Rate of Aircraft Cabin Materials I the Ohio State University Apparatus

Details

• Creators:
  Lyon, Richard E. ; Fulmer, Matthew ; Walters, Richard ; Crowley, Sean
• Corporate Creators:
  United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center
• Subject/TRT Terms:
  Air Flow Calorimeters CFR 25 Combustion Chambers Error Flammability Flammability Tests Heat Heat Release Rate OSU Repeatability Reproducibility Temperature

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• Publication/ Report Number:
  DOT/FAA/TC-TN15/34
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center
• Abstract:
  Materials for aircraft cabin interiors must meet the flammability requirements of Title 14 Code of Federal Regulations (CFR) Part 25.853. The 14 CFR 25.853 requirement includes a test for large-area materials that measures the heat release rate (HRR) during burning using a fire calorimeter originally developed at Ohio State University (OSU). In the standard 14 CFR 25 procedure, a sample is inserted into the combustion chamber of the OSU apparatus and subjected to a calibrated radiant heat flux of 35 kW/m2 and an impinging pilot flame. Room temperature air is forced through the combustion chamber and exits through the exhaust duct at the top of the apparatus where a thermopile senses the temperature of the exhaust gases. The HRR during the test is deduced from the sensible enthalpy rise of the air flowing through the combustion chamber using the temperature difference between the exhaust gases and the ambient incoming air to calculate the amount of heat released by burning after suitable calibration using a metered methane diffusion flame. Limits of 65 kW/m2 and 65 kW/m2-min for the maximum (peak HRR) and the total heat release (HR) up to 2 minutes into the test (2-min HR), respectively, are placed on large-area materials used in passenger cabins of transport category airplanes carrying more than 19 passengers.
  
  Results from multi-laboratory studies of the same materials tested for HR and HRR according to 14 CFR 25.853 indicated that the laboratory-to-laboratory variation of the test results was relatively high. There are many factors that can contribute to poor agreement between OSU fire calorimeter results obtained in different laboratories (i.e., reproducibility), including the accuracy of the heat flux calibration, contaminated temperature sensors, thermal inertia of the apparatus and its components, and changes in the convective environment in the combustion and bypass chambers caused by airflow and airflow distribution. This study focused on the effect of the airflow through the 14 CFR 25.853 fire calorimeter on the repeatability and reproducibility of the HR and HRR by the sensible enthalpy (temperature rise) of the standard method, compared to HR and HRR measured simultaneously by the oxygen consumption method.
  
  
• Format:
  PDF
• Collection(s):
  FAA Fire Safety FAA William J. Hughes Technical Center for Advanced Aerospace
• Main Document Checksum:
  urn:sha-512:5be208e9252dbbefa9e7a8f2f184e0a2b9c9f79998f7b599ff1b2df2d0503a6789aa84d2d23413902beae5bab6edf009d1e5099f3946f4d19e06ff644cff1193
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/57853/dot_57853_DS1.pdf
• File Type:
  [PDF - 870.10 KB ]