# Fire Risk Analysis in Large Multi-Compartment Structures Using a Hybrid Multiscale Approach
## 5 Conclusions  
This paper presents a hybrid multiscale approach to produce real-time fire and smoke maps in large multicompartment structures. The proposed approach is based on a network model, whose inputs are determined from two validated models, namely a zone model and a 1D CFD model. Two demonstration cases for a four-story office building and a generic military corvette are presented herein. For the first one, a statistical study is conducted to produce fire risk maps, ranking the building compartments by to their propensity to burn or generate fires of varying severity, and identifying the sensitive and vulnerable areas to be defended. At this stage of development, smoke transport is calculated by a simple filling model whose limits are identified, by comparing results from such a model with results from a validated 3D CFD software for the building application. A good agreement is found when smoke propagation is not influenced too much by the entire building system and its ventilation. Otherwise, when a strong two-way interaction exists, the agreement degrades. Although further work is needed to improve the modeling of smoke transport, we believe that the hybrid approach could be the basis of a decision support tool, ranging from simple sizing of fire detection and control systems, or design of less vulnerable architectures, to fire risk prevention and real-time fire management in multicompartment structures and the training of firefighting staff. The hybrid approach allows modelers to extend the computational domain and explicitly examine an entire system that may have hundreds or even thousands of compartments. This could only be achieved with a CFD code (due to the computational resources it would require) by simplifying the geometry of the system or by considering only a part of the total system and expand conclusions to the entire system [1]. The hybrid method therefore appears to be a good compromise between accuracy and simulation time to simulate fire and smoke propagation in very large structures, with time constraints being a permanent challenge in fire safety engineering.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app12094123/s1](https://www.mdpi.com/article/10.3390/app12094123/s1)]([https://www.mdpi.com/article/10.3390/app12094123/s1](https://www.mdpi.com/article/10.3390/app12094123/s1)): Figure S1: Deck plans of the corvette, showing ceiling insulation; Figure S2: Deck plans of the corvette, showing bulkhead and hull insulation.  
Software, N.D. and N.S.; conceptualization, methodology, and writing--original draft, B.P.; investigation, Y.P., M.M. and P.P.; project administration, J.L.; data curation, T.P. and D.A. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Association Nationale de la Recherche et de la Technologie ANRT under CIFRE grant n\({}^{\circ}\) 2017/1739. and jointly by the Delegation Generale de l'Armement DGA and the Agence Nationale de la Recherche ANR under grant n\({}^{\circ}\)ANR-17-ASMA-0005.  
Not applicable.  
Data Availability Statement: Data supporting the results of this study are available on request from J.L.  
The authors wish to express their thanks for the financial support of ANRT, DGA, and ANR.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.