The influence of low air pressure on horizontal flame spread over flexible polyurethane foam and correlative smoke productions

摘要: Abstract Pressure effects on quasi two-dimensional flexible polyurethane (FPU) foam flame spreading behavior, typical product concentrations, and smoke detector responses were investigated by comparative experiments under different ambient pressures of 99.8 kPa (in Hefei) 66.5 kPa Lhasa), respectively. First, significant decreases velocity burning rate observed low pressure condition. Averaged global was found to be dependent pressure, with an exponential factor 4/3 theoretically based modeling. Second, the maximum temperature at a given position in axial thermal plume showed insensitivity yet ceiling jet obviously higher. Third, shown have no effect soot particles size distribution scan electron microscopy (SEM) imaging. However, number concentration decreased reduced attributed much slower formation pressure. This result would further interesting influence response signals photoelectric ionization detector. Finally, variation CO O 2 volume discussed. Considering relatively small heat release for FPU selected, far-field lower enhanced diffusive effect.