# Fire Risk Analysis in Large Multi-Compartment Structures Using a Hybrid Multiscale Approach
## 3 Proof of Concept
### Application to a Full-Scale Generic Military Corvette
#### 3.2.1 Zone Model Results  
For both scenarios, the zone model was applied to describe the fire development and smoke production in the 96 fire-prone compartments of the corvette, for a total of 184 simulations. Combustion properties of the equivalent fuels in Table 5 are available in [20].  
The example of the accommodation compartment E112 is given below for the first scenario (i.e., ventilation was off). Compartment E112 measures 7 m \(\times\) 3.7 m \(\times\) 3 m. It is made of 1 cm thick bare steel walls, has an upward opening of 0.81 m\({}^{2}\) to room E0012, and has a 2 m \(\times\) 1 m door to corridor E110. The prescribed HRR time curve in E112 is evaluated using the values of the parameters in Table 5 and the strategy presented in [14] for compartments where multi-fuel combustion occurs. The design fire of E112 is plotted in Figure 21.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Material** & \begin{tabular}{c} **Conductivity** \\ **(W/m/deg.)** \\ \end{tabular} & \begin{tabular}{c} **Density** \\ **(kg/m\({}^{3}\))** \\ \end{tabular} & \
\begin{tabular}{c} **Specific Heat** \\ **(J/kg/deg.)** \\ \end{tabular} &
\begin{tabular}{c} **Emissivity** \\ \end{tabular} \\ \hline Steel & 54 & 7850 & 470 & 0.95 \\ Rockwood UMPA 24 & \(6.026\times 10^{-7}T^{2}-2.245\times 10^{-4}T+4.840\times 10^{-2}\) & 24 & 1000 & 0.9 \\ Rockwood UMPA 36 & \(3.358\times 10^{-7}T^{2}-5.595\times 10^{-5}T+2.107\times 10^{-2}\) & 36 & 1000 & 0.9 \\ Rockwood UMPA 66 & \(1.856\times 10^{-7}T^{2}-6.636\times 10^{-6}T+1.345\times 10^{-2}\) & 66 & 1000 & 0.9 \\ Glass wool PI 662 & \(0.037\) & 16 & 1000 & 0.9 \\ Rockwood SEAROX & \(5.0\times 10^{-7}T^{2}-1.332\times 10^{-4}T+3.254\times 10^{-2}\) & 100 & 1000 & 0.9 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Thermal properties of the constituent materials of corvette bulkheads (manufacturer’s data).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Type of** & **Content** & **Equivalent** & \(m_{0}^{\prime\prime}\) & \(a_{gr}\) & \(p\) & \(HRR_{max}\)\({}^{1}\) & \(A_{f}/A_{F}\)\({}^{2}\) \\  
The times of the fire phases and barrier failures in E112, as well as the time evolution of the mass flow rate, temperature, and density of the smoke leaving E112 were calculated using the zone model. Flashover, decay, and extinguishment take place after 12\({}^{\circ}\)5\({}^{\prime\prime}\), 16\({}^{\prime}\)00\({}^{\prime\prime}\), and 21\({}^{\prime}\)21\({}^{\prime\prime}\), respectively. Due to the thermal properties of bare steel, the durations of the fire resistance of the walls are relatively short, namely 14\({}^{\prime}\)30\({}^{\prime\prime}\), 15\({}^{\prime}\)11\({}^{\prime\prime}\), and 19\({}^{\prime}\)44\({}^{\prime\prime}\) for the side walls, ceiling, and floor, respectively. Although not shown here, the smoke mass flow rate reaches its maximum value in 15\({}^{\prime}\), i.e., 2.8 kg/s; it then remains constant for 10\({}^{\prime}\) and gradually decreases. The smoke temperature reaches 550 \({}^{\circ}\)C at the moment of flashover, then continues to increase until it reaches 610 \({}^{\circ}\)C after 25\({}^{\prime}\) of fire. At this moment, the density is minimum, with 0.4 kg/m\({}^{3}\).