Numerical modeling of flexible polyurethane foam combustion under two ignition modes

The combustion process of flexible polyurethane foam (FPUF) is accompanied by the release of toxic flue gas and the combustion flow behavior of liquid products. There are great potential safety hazards. The complex combustion behavior of FPUF is a challenge to numerical modeling. Although the existing two-layer combustion model of FPUF generally reflects the segmentation of heat release rate (HRR) during FPUF combustion, there is still a certain deviation between the modeling and the experimental results. According to the experimental results of FPUF in thermogravimetry (TG) and cone calorimeter (CONE), the two-layer modified models of piloted ignition and non-piloted ignition combustion of FPUF in CONE were established by fire dynamics simulator (FDS), and the modeling results were compared with the experimental results. The results show that the HRR, smoke temperature at the peaking stage, the volume percentage of CO2, and the volume percentage of CO predicted by FDS are in good agreement with the experimental results in two ignition modes when the external radiant heat flux is between 30 similar to 50 kW m(-2). When the external radiant heat flux is less than 30 kW m(-2), the FDS prediction result deviates greatly from the experimental result in the non-piloted ignition mode.