Abstract: In the tunnel environment, the combustion dynamics of spill fires, encompassing phenomena such as flame bifurcation fusion, oscillations, and tilting, coupled with the fluidic behavior of diffused fuel layers and heat transfer interactions with the tunnel's bottom wall and flame smoke, exhibit significant complexity and instability. These complexities heighten the risk of igniting neighboring combustible materials, posing significant threats to human life and property safety. The present study delves into a comparative analysis of the diffusion, combustion characteristics, flame height, oscillations, heat radiation models, heat transfer mechanisms, smoke dissemination, and ceiling temperature escalation models of oil spill fires in both open spaces and tunnel environments. Notably, it highlights the need for further research to refine our understanding of flame oscillations, heat radiation models, and other flame behavioral patterns. By elucidating the heat transfer mechanisms, unsteady combustion dynamics, and smoke dispersal dynamics of spill fires, this work provides vital theoretical and technological underpinnings for the prevention and emergency response strategies against tunnel flow fires.

Key words: tunnel flowing fire, radiation heat feedback, flame behavior, smoke exhaust