Benchmarking the ignition prediction capability of B-RISK using furniture calorimeter and room-size experiments.
Thesis DisciplineFire Engineering
Degree GrantorUniversity of Canterbury
Degree NameMaster of Engineering in Fire Engineering
A fire zone model called B-RISK has been developed and part of this work is to benchmark its capability to predict item ignition in multi-object compartment fire simulations. A series of fire experiments have been conducted which measured single item ignition times under the furniture calorimeter and in the ISO 9705 room. These experiments used mock-up furniture items created from three common materials found in most households in New Zealand. B-RISK uses the flux time product (FTP) method to predict ignition of items based on radiation received using the point source model (PSM). This thesis presents an analysis of the B-RISK predictions compared to the experimental measurements. Due to the mathematical formulation of the PSM and FTP method, it is found that the predicted ignition time is sensitive to the distance between the radiative source and the item. Predicted ignition times of armchairs constructed of PU foam were within 14% of the ISO 9705 room experimental results. However for the furniture calorimeter experiments it is found that to get reasonable predicted ignition times for the mock-up armchair and TV items there is a need to account for the burner flame movement by adjusting the radial distance. Direct flame contact was required to ignite the mock-up cabinetry items and B-RISK was unable to successfully predict this ignition time.