Emergency evacuation assessment of blended-wing-body aircraft based on dynamic risk model: A comparative study

The high passenger capacity and multi-compartment structure of Blended-Wing-Body (BWB) aircraft introduce new challenges for emergency evacuation. However, existing airworthiness standards, which are established based on conventional tube-and-wing aircraft, primarily assess safety through overall evacuation time, overlooking the dynamic propagation of risks in fire scenarios. To address this limitation, this study develops a fire-coupled occupant evacuation model and proposes a dynamic risk assessment framework that integrates cabin layout, evacuation pathways, and fire dynamics. By comparing the evacuation performance of a 380-seat BWB aircraft and an A350-900 under identical fire intensity conditions, the study suggests a potential for enhanced evacuation safety performance of the BWB configuration, attributed to its ability to effectively mitigate heat radiation and toxic gas dispersion. Furthermore, the conventional assessment model is refined by introducing a coupled criterion between the dynamic risk index R h and the Required Safe Egress Time (RSET), improving the robustness of localized risk evaluations. This method provides theoretical support for optimizing BWB cabin layouts and designing effective emergency response strategies.