Full-Scale Vehicle Burn Test of a 2013 Sedan in a Wildfire Setting 2024-01-2503

A burn test was conducted to evaluate the propagation of a fire from burning vegetation underneath a vehicle. A 2013 four-door sedan was instrumented with thermocouples throughout the engine compartment, interior, underbody, and trunk as well as a heat flux sensor underneath the vehicle. The vehicle was placed on a bed of straw to simulate a wildland fuel load. The fire was ignited in the vegetation under the engine compartment near the driver-side front wheel. Initially the fire spread outward from the point of origin under the vehicle. As the fire grew, it spread to the engine compartment and travelled through the vegetation outside of the footprint of the vehicle. The fire progressed rearward along the outside of the vehicle while the fire under the engine compartment continued to grow. During the test, the front and rear driver-side doors were opened at t=1.00 min. and t=1.15 min., respectively. At approximately 1.75 min. after ignition, the temperature in the front of the passenger compartment of the vehicle began to increase. By t=1.9 min., the temperature within the passenger compartment of the vehicle was over 600 °C. The fire was extinguished at t=2.33 min. After the fire, the vehicle was examined for potential pathways the fire took to propagate to the vehicle interior. It was observed that the open driver-side doors were the dominant avenue for fire propagation to the interior of the vehicle. The heat flux from the wildland fuel load was measured to be similar to the heat flux measured in a post-collision fire test involving a gasoline pool fire underneath the vehicle.