# GoZone: A Numerical Model for Travelling Fires Based on Cellular Automata Concept
## 8 Comparison with Veseli Travelling Fire Test  
The Veseli fire test was aimed at investigating the fire dynamics and temperature distribution of a fuel controlled fire in a large open compartment in a two-storey building (Czech Republic, 2011) [58]. The compartment size was 10.4 m \(\times\) 13.4 m on the floor and 4 m in height. The fire load was made of wood cribs with sticks of dimensions of 50 mm \(\times\) 50 mm \(\times\) 1000 mm with a moisture content of 12%. A linear channel filled with \"_petroleum_\" was used for the ignition of the fire. There was a 5 m wide and 2 m high opening in one of the long walls (Figure 20). The gas temperature in the compartment was recorded during the test at different locations whereas the fire behaviour was recorded on camera. Information not directly measured during the test was evaluated numerically by [PERSON] et al. by a CFD based simulation performed with FDS [58]. The test compartment as well as the GoZone model are as shown in Figure 20.  
Figure 19: Gas temperature evolution: GoZone, measured, FDS simulation [22]: (a) Crib line 2; (b) Crib Line 6; (c) Crib line 10. For the model in GoZone, the fire load area was discretised by a structured mesh with 24 cells of 1 m\({}^{2}\) (blue cells in Figure 1(b)) according to Section 5. The green cells do not contain any fuel and the red cell is the cell of origin of the fire. The comparison with GoZone is meant to be a priori, thus the values of the fuel load density, the rate of the heat release density, and the fire growth rate assigned to the fuel were taken according to the insights given by the authors of the test [49] (see Table 7). The critical energy and the critical heat flux were taken consistently with the outcomes of Section 3. The power released by the fire as a function of time was not directly measured during the test, however, it was evaluated a posteriori by means of the CFD based model with the software FDS [49]. Figure 21 shows the comparison between the results from FDS and GoZone. The peak value of the power as well as the peak time and the total duration were in the same order of magnitude with differences compared to a FDS of \(-8\%\), \(-10\%\), and \(-4\%\), respectively. A discrepancy can be noticed in the first phase, when FDS accounts for the petroleum burned as means of ignition, which was not the case in GoZone. \begin{table}
\begin{tabular}{c c c c c} \hline
**Fuel Load** & **Rate of Heat Release** & **Fire Growth** & **Critical Energy** & **Critical Heat** \\
**Density [M]/m\({}^{2}\)]** & **Density [kW/m\({}^{2}\)]** & **Rate [s]** & **[kJ/m\({}^{2}\)]** & **Flux [kW/m\({}^{2}\)]** \\ \hline
680 & 700 & 300 & 400 & 12.5 \\ \hline \end{tabular}
\end{table} 
Table 7: Main input simulation of the Veseli fire test. Figure 21: Comparison of the power released in the Veseli fire test. Figure 20: Plan view of the Veseli fire test: (**a**) reality; (**b**) GoZone model. The fire evolution has been described by [PERSON] et al. and [PERSON] et al. [49; 58; 59]. The fire development was characterised by three main phases: phase I, from 0 to 15 min, when the fire leading edge spread along the fuel bed; phase II, from 20 to 25 min, when post-flashover conditions were observed; and phase III, from 25 to 40 min when the fire trailing edge progressed to the end of the fuel bed, characterised by a decay of the fire. In Figure 22, the fire evolution is shown through a comparison between pictures taken during the test (from [PERSON] et al. [9]) and images from the GoZone Graphical User Interface (GUI). Pink cells represent a fire in its decay phase and black cells are painted where the fuel has been consumed completely. Figure 22: Cont. Moreover, it has been observed that the fire spread rate varied during the first phase. [PERSON] et al. [49] provided an estimation of the position of the leading edge of the fire up to the moment when the fire covers the whole fuel bed surface (end of phase I).