These slides were presented at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

This paper demonstrates the workflow of conducting a simulation of electric vehicle (EV) fire in urban settings using commercial software. This methodology assesses the fluid-structure interaction of flame propagation on urban structures to provide a comprehensive structural assessment. Today, climate change is one of the most pressing global challenges. The rate at which global temperatures are rising have tripled since the 1850s and 2024 is on track to be the hottest year on record. As global warming continues, there is an urgent and unavoidable need to develop strategies to combat climate change. One of these strategies is the shift from internal combustion engine (ICE) vehicles to electric vehicles (EVs). EVs operate on batteries and offer a cleaner alternative to traditional ICE vehicles that emit pollutants into the atmosphere. As such, cities today are undergoing rapid electrification in the field of transportation. However, while efficient, batteries pose significant hazards to both individuals and property. Under mishandling or malfunction, the batteries are susceptible to fires resulting from thermal runaway which is an uncontrollable state that results in the release of heat energy, toxic gases and smoke. Unlike conventional fires, battery fires are exceedingly difficult to extinguish, often leading to prolonged, self-sustaining flames that resist standard firefighting efforts. In extreme cases, thermal runaway can also result in explosions. Unfortunately, there has been an alarming increase in battery related fires, damages and even fatalities in the recent years. As EVs and battery technologies continues to evolve, it becomes necessary for better battery safety measures to be implemented globally. This naturally calls for further study, such as battery safety assessments through simulations. However, existing literature is limited to the fluid domain, usually focusing on the effects of toxic gas and fire propagation. In the dense concrete jungles of the metropolises today, accurate structural effects must be accounted for comprehensive assessment. The commercial computational fluid dynamics (CFD) software FLACS is employed to simulate the dispersion effects and propagation of fire. The unique distributed porosity concept in FLACS allows for effective multiscale modelling. Selected parameters such as temperature and overpressure are tabulated. Subsequently, these will form the inputs for our structural analysis in the Finite Element solver. Geometries representative of urban environments will be subjected to these loads, offering a comprehensive multiphysical assessment of both fluid (e.g. concentration of toxic gas) and structural effects in cities.