Battery pack jet fire modeling and vehicle fire spread simulation in Ro-Ro ships

To investigate the fire spread patterns of multiple vehicles within PCTC (Pure Car and Truck Carrier) under the influence of jet fire. This study proposed an equivalent material and constructed a homogenized BEV fire model that can change in real time according to the heating conditions, avoiding the fire from developing at a fixed heat release rate. At the same time, a battery pack jet fire model suitable for large-scale simulation was constructed. Subsequently, these two models were combined to explore the fire spread patterns and hazard areas under different jet fire directions. The results show that the ceiling jet is the main cause of ignition of surrounding vehicles, and thermal radiation is the main way of vehicle ignition. Reducing the vehicle spacing and the outbreak of jet fire significantly accelerates the development of the fire, with the maximum increase in the fire heat release rate reaching 54.6%. Among them, the jet fire to the right is the most dangerous, which can advance the ignition time of the adjacent vehicle by 70.2 s. Based on the critical heat flux criterion for area classification, the expansion of the hazardous region within 0.2 m is relatively slow. At a distance of 1.8 m, the left and front sides of the burning vehicle remain in a low-risk state for 274.2 s and 377.4 s, respectively. This research can provide model support and theoretical basis for large-scale vehicle fire simulation and PCTC fire prevention. • Proposed a jet fire model and an equivalent material for battery vehicle fire. • Proposed a quantitative zoning method for vehicle fire hazard area. • Ceiling jet is the primary inducement for igniting non-adjacent vehicles.