A CFD Based Multi-Physics Modeling Approach to Predict Vent Gas Flow Paths due to Can Melting during Prismatic Cell Thermal Runaway

As the automotive industry increasingly adopts high-energy-density pouch cells, ensuring vehicle safety against catastrophic thermal runaway (TR) has become paramount. Predicting the complex failure sequence of pouch cells, requires high-fidelity simulation tools that can capture tightly coupled physical phenomena. This paper presents a comprehensive, three-dimensional multi-physics Computational Fluid Dynamics (CFD) framework designed to simulate the entire TR event. The simulation originates with a multi-step Arrhenius chemical kinetics model to calculate the heat and gas generated by the primary exothermic reactions. This process drives a rapid increase in internal temperature and pressure, which is resolved by the model’s fluid dynamics solver. The initial vent opening is triggered when this internal pressure exceeds a predefined mechanical burst threshold, simulating a realistic seal rupture. Concurrently, a Conjugate Heat Transfer (CHT) analysis calculates the temperature distribution throughout the solid cell components. These predicted high temperatures are then utilized by a solidification/melting phase-change model to account for the subsequent melting of the aluminum can material. This melting creates additional, evolving pathways for the venting of internally generated gas. By integrating these distinct but interconnected failure mechanisms, the framework provides a high-fidelity analysis of the complete TR sequence, serving as a critical engineering tool for the development of safer battery systems.