Integrated Analysis of Ventilation System Efficiency and Lifesaving in Tunnel Fire Conditions

This scientific article explores the critical relationship between ventilation system efficiency and human survival during fire incidents in road tunnels. Through the analysis of several historical tunnel fires, the research confirms that ventilation systems, although essential, are not sufficient on their own to guarantee life safety. These findings highlight the need for comprehensive models that integrate various influencing factors. A new methodological approach is proposed, emphasizing the importance of the Dynamic Efficiency Factor (DEF) — an integrated parameter that evaluates the joint impact of fire dynamics, ventilation efficiency, and human evacuation risks. The DEF concept introduces a holistic framework that links technical performance with human behavioral models in emergency situations. Computational Fluid Dynamics (CFD) simulations are employed to model the development of fires, temperature gradients, smoke propagation, and toxic gas dispersion. The analysis demonstrates that while the Froude number remains a crucial indicator for assessing ventilation performance, in real scenarios it fluctuates significantly. As such, reliance solely on the Froude number without adaptive corrections can lead to insufficient planning for fire emergencies. One of the key challenges addressed in this study is the integration of CFD models with evacuation simulations. Differences in temporal and spatial resolution between the models complicate the integration process, yet overcoming these difficulties is essential for accurate risk assessment. The paper presents specific practical examples and outlines strategic recommendations for establishing effective, combined modeling methodologies. Ultimately, the study concludes that achieving a reliable fire safety system requires more than just mechanical installations. It necessitates well-designed procedures, refined engineering approaches, robust management strategies, and close consideration of human factors. By applying such a multifactorial and dynamic framework, emergency planning for tunnel fires can become more resilient and effective, enhancing both structural safety and occupant survival prospects.