Experimental Study on Car Fire with Respect to Urban Fire Spreading

In case of urban large fire spreading in a highly crowded areas of Japan, roads are usually considered to be effective in blocking the fire spreading between the buildings, together with parks, vacant spaces, rivers, and railway tracks, etc. However, especially when there is a car in a narrow road between two adjacent buildings, then it could be possible that fire spreading will be even accelerated by the burning car on a road, rather than the situation where a road will block the fire spreading. Both domestically in Japan and internationally, there have been many car fire researches based on experiments, but so far, most of them have been discussing the fire behavior of automobiles themselves, and not so many have been focusing on the car fire with respect to fire spreading between the buildings in case of urban fire spread, under the circumstances such as major earthquake or extremely high wind. Therefore, in this research, authors firstly conducted the full-scale fire experiment, where car is ignited by fire from the opening in a building façade, and observed how car is ignited by radiation and convection and then how fire is propagated in that car, and also incident heal fluxes were measured at surrounding places of the ignited car. Furthermore secondly, simple calculation model was proposed based on this car fire experiment, which was then applied to the parametric study for predicting the occurrence time of fire spreading to the adjacent building from the building of fire origin, with and without a car located between the two buildings. It was found that generally there was not great difference in time to fire spreading between the buildings dependent on the existence of car. But in an extreme situation where the distance between the two buildings is large, and also car is located quite close to the adjacent building (instead of the building of fire origin), there was a difference in calculation results dependent on the existence of a car, more specifically, the existence of car induced the occurrence of fire spreading between the buildings.