## 3 Results and Discussions  
### Flame Evolution  
For the free-burning N-heptane pool fire, a high concentration of fuel vapor was present above the pool surface with insufficient oxygen. However, for the pool fire burning in ventilated conditions, the amount of oxygen near the fuel surface was supplemented, and the heat feedback changed, leading to changes in the evolution of wind-blown pool fires [15; 16; 17]. The coupling effect of flame buoyancy and wind drives flame behaviors, which tilts the flame and changes its geometry. The presence of a blockage baffle enhances the interaction between the crosswind and fire and consequently creates complex turbulent flow conditions.  
Figure 2 displays the baffle height's influence on flame shape changes in the pool fire in the experimental section at a 3 m/s crosswind. After igniting, the flame quickly spread across the pool, and the flame size increased until a stable regime was established. Then,  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**No.** & **Baffle Height (H cm)** & **Crosswind Velocity (V m/s)** \\ \hline
1–6 & 2 & 0, 1, 2, 3, 4, 5 \\ \hline
7–12 & 4 & 0, 1, 2, 3, 4, 5 \\ \hline
13–18 & 6 & 0, 1, 2, 3, 4, 5 \\ \hline
19–24 & 8 & 0, 1, 2, 3, 4, 5 \\ \hline
25–30 & 10 & 0, 1, 2, 3, 4, 5 \\ \hline \hline \end{tabular}
\end{table}
Table 1: A summary of the experimental and simulation scenarios.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Material** & **Density** & **Special Heat** & **Thermal** & **Absorption** & **Heat of** & **Boiling** \\  & **(kg/m\({}^{3}\))** & **Capacity** & **Conductivity** & **Coefficient** & **Reaction** & **Temperature** \\  & **(kJ/kg:k)** & **(W/m\(\cdot\)k)** & **(m\({}^{-1}\))** & **(kJ/kg)** & **(\({}^{\circ}\)C)** \\ \hline \multicolumn{1}{c}{Heptane} & 675 & 2.24 & 0.14 & 333 & 317 & 98.5 \\ \hline \multicolumn{1}{c}{Steel} & 7850 & 0.46 & 45.8 & - & - & - \\ \hline \hline \end{tabular}
\end{table}
Table 2: Thermal characteristic parameters of heptane and steel.  
the fire gradually decreased until it was extinguished owing to a lack of fuel. As the baffle height increased, the flame body became brighter, and the flame volume expanded. When the height of the baffle in front of the wind-blown flame increased from 2 to 10 cm, the burnout time reduced from 360 to 211 s. The entire combustion process can be separated into three stages: the initial burning stage, steady combustion stage, and decline stage. Figure 3 depicts the pool fire flame shape under a stable combustion stage at a 0-5 m/s crosswind velocity. When the wind speed increased from 1 to 2 m/s, the flame length above the baffle was significantly reduced due to the high wind speed which prevented the fuel vapor from timely combustion and reaction. Meanwhile, due to the increase in wind speed, the turbulence and velocity in the backflow area behind the baffle also increased. The flame under the baffle had a full combustion reaction. The combustion intensity increased, and the brightness of the flame increased. When the baffle height increased, the flame morphology changed from an inclined cone shape to a curved shape with a corner. When the baffle height was 2 cm, the flame morphology was similar to that without the baffle, with the flame inclined downstream. When the height of the baffle increased to more than 4 cm, it can be seen that the flame bent. The lower part shows the vertical flame close to the baffle and the upper part shows the flame inclined in the downstream direction.