Pressure Modeling of Vertically Burning Aircraft Materials.

摘要

The possibility of evaluating relative rates of upward fire spread on aircraft cabin materials is investigated with small-scale models burned at elevated ambient air pressure. The modeling technique, which preserves the fluid Grashof number of the full-scale fire spread process, is verified in the first part of the study with vertical walls of polymethyl methacrylate (PMMA) fuel ignited at one atmosphere (full-scale) and at elevated absolute pressures (model) to 3.5 MPa (515 psia). In the second phase of the study, fifteen aircraft cabin samples are subjected to a small PMMA ignition source for a range of elevated ambient air pressures. Rates of upward fire spread, characterized by flame height exponential growth factors, are measurable for nearly all the aircraft cabin materials at absolute pressures from 1.18 MPa (165 psia) to 3.2 MPa (465 psia). Ranking of the materials by rate of upward fire spread is facilitated by the nearly two order of magnitude separation between highest and lowest growth factor at each pressure level. This ranking is found to be reasonably independent of pressure, enabling conservative predictions of upward spread behavior at one atmosphere to be made. (Author)