## 2 Literature Review  
In previous research, the causes and the propagation laws of EV fire accidents have become a welcome topic. Many studies put a lot of effort to investigate the fires with their influences in different scenarios [7; 8]. [PERSON] [9] sorted out the cases and tests of EV fire accidents and identified that their peak heat release rate (PHRR) ranged from 4.2 to 7 MW with the total heat release between 4.7 and 8.5 GJ. [PERSON] [10] and [PERSON] [11] conducted full-scale vehicle combustion tests under different thermal runaway excitation conditions. They studied the processes of thermal runaway in a battery pack, the flame development and spread and the flame extinction and suppression. The time-sequence curves of the various stages of thermal runaway combustion in EVs were monitored and recorded and the sequence of each key point in the development process was obtained. These issues raise concerns about the fire safety of EVs and the power lithium-ion battery energy systems. The process of the EV fires was determined through the study of accident cases or full-scale experiments. In an EV fire accident, the heat convection and thermal radiation generated by the combustion are important causes of the thermal injury to pedestrians. Furthermore, the shape of the flame is one of the factors that affects the heat convection and thermal radiation of the combustion. Jet flames [12] and pool flames [13] are the two general flame forms in flame dynamics. In the early stage, the EV fire was approximately a thermal runaway flame stemming from the lithium-ion battery, which conformed to the jet flame characteristics. After the lithium-ion battery fire spread to the entire vehicle, the flame shape resembled a small pool fire. The flame model of an EV fire can be simplified by approximating the shape of the flames at the different stages of the vehicle combustion. In a study on the calculation method and model of the thermal transfer of EV fires, [PERSON] [14] evaluated the severity of the parking lot fire based on the total energy released by the combustion. [PERSON] [15] proposed a control method based on the different environmental conditions of an indoor parking lot by analyzing the causes and effects of vehicle fires. [PERSON] [16] applied the flux-time product ignition criterion and the PSM of the flame radiation to predict the complex problem of multiple-vehicle ignition. [PERSON] [17] considered the thermal radiation range as the main consideration, simplified the flame thermal radiation model using the SFM and evaluated the fire impact range by determined the safe distance. These issues focused more on EV fires in confined spaces rather than open spaces. In addition, research on outdoor fires has mainly focused on wildfires [18; 19] and research on outdoor EV fires is insufficient. However, compared to the study of fire dynamics, there are few in-depth studies on the laws of pedestrian thermal injury related to the EV fires. Research on pedestrian evacuation strategies in fires mostly consider confined-space scenarios, such as subways, tunnels and indoor spaces, and relevant research on outdoor scenarios with more complex environments has not been conducted so far. [PERSON] [20] used the cellular automata to construct a flame and smoke spread process in a fire and simulated the evacuation movement of the pedestrians. [PERSON] [21] used computational fluid dynamics (CFD) to simulate the flame propagation and the pedestrian evacuation processes in typical scenarios. [PERSON] [22] used the improved Dijkstra algorithm, considering the minimum total time of the pedestrians passing through the evacuation route as the optimization objective. [PERSON] [23] conducted pedestrian flow experiments in a corridor scenario of fire evacuation and proposed a functional relationship between the pedestrian flow density and the pedestrian flow velocity.