Fire modelling enables the prediction of potential hazards for humans and structures. This is one of the methods used in fire risk mitigation, especially for underground transportation facilities. Novel automotive technologies are becoming increasingly popular around the world, but they also bring new challenges in terms of fire safety. Electric vehicle (EV) fires are characterized by rapid growth and heat release due to potential battery failure and the thermal runaway process. [1–3]. It is observed in heat release rate (HRR) curves in comparison to conventional vehicles. In the face of these fire hazards, it is essential to properly design fire safety systems. This study attempts to establish to numerical modelling, the performance of water-based fixed firefighting systems (FFFS) in suppression of electric vehicle fire. Simulations were run using the Computational Fluid Dynamics (CFD) code ANSYS Fluent with sub-models following the main physical processes as heat transfer, species transport, turbulent flow and combustion reaction. Numerical domain of the experimental setup was prepared and discretized using the Finite Volume Method (FVM) by polyhedral elements. Water droplets were simulated using the Lagrangian method through the Discrete Phase Model (DPM) for injection parameters, particle trajectories, heat, and mass transfer with a continuous gas phase of control volumes. The validated CFD-DPM numerical model allows estimating the cooling effect by monitoring the amount of heat consumed for the evaporation of water particles. Numerical study simulates full-scale fire experiments conducted at Centro Experimental de San Pedro de Anes of Applus+ TST laboratory in Siero, Asturias, Spain. The following figure shows the initial phase of the EV fire in the experiment and the simulation results of the incident radiation of EV engulfed in flames. [1] P. Sturm, P. Fößleitner, D. Fruhwirt, R. Galler, R. Wenighofer, S.F. Heindl, S. Krausbar, O. Heger, Fire tests with lithium-ion battery electric vehicles in road tunnels, Fire Saf. J. 134 (2022) 103695. [2] S. Kang, M. Kwon, J. Yoon Choi, S. Choi, Full-scale fire testing of battery electric vehicles, Appl. Energy 332 (2023) 120497 [3] P. Sun, R. Bisschop, H. Niu, X. Huang, A Review of Battery Fires in Electric Vehicles, Fire Technology 2020 56:4 56 (2020) 1361–1410