# Experimental Study of Explosion Mitigation by Deployed Metal Combined with Water Curtain
## 3 Results
### Free Field
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Experiment Type** & \begin{tabular}{c} **Overpressure** \\ **Control (Bar)** \\ \end{tabular} & \begin{tabular}{c} **Overpressure** \\ **Wall (Bar)** \\ \end{tabular} & **Attenuation (\%)** & \
\begin{tabular}{c} **Overpressure** \\ **Ground 1 (Bar)** \\ \end{tabular} &
\begin{tabular}{c} **Overpressure** \\ **Ground 2 (Bar)** \\ \end{tabular} \\ \hline no plate & 0.90 & 2.53 & - & 3.20 & - \\ no plate & 0.89 & 2.61 & - & 3.22 & - \\ no plate & 0.89 & 2.70 & - & - & - \\
2 expanded metal & 0.90 & 1.05 & 60 & 3.08 & 2.12 \\
2 expanded metal & 0.86 & 0.88 & 66 & 2.26 & 1.96 \\
2 expanded metal & 0.89 & 0.99 & 62 & 3.31 & 2.14 \\
2 expanded metal \& water & 0.89 & 0.90 & 66 & 1.88 & 1.89 \\
2 expanded metal \& water & 0.78 & 0.68 & 74 & 3.17 & 1.83 \\
1 expanded metal & 0.89 & 1.42 & 46 & 3.16 & - \\
1 expanded metal & 0.82 & 1.78 & 32 & 3.52 & - \\
1 expanded metal & 0.84 & 1.40 & 47 & 3.62 & - \\
1 expanded metal \& water & 0.80 & 0.82 & 69 & 2.80 & - \\
1 expanded metal \& water & 0.76 & 0.75 & 71 & 3.08 & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Initial overpressure collected by three sensors (control, inserted into the wall and laid on the ground) for all experiments. The attenuation of the overpressure measured on the wall relative to the mean value obtained by the reference tests (no plate) is also given. Overpressure ground 1 and overpressure ground 2 correspond to the maximum value of the first and the second peak, respectively. Figure 13: Reflected pressure measured on the wall for one test of each configuration. One reference test is also shown. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Experiment Type** & \begin{tabular}{c} **Impulse Control** \\ **(Bar-s)** \\ \end{tabular} & \begin{tabular}{c} **Impulse Wall** \\ **(Bar-s)** \\ \end{tabular} & \begin{tabular}{c} **Attenuation** \\ **(\%)** \\ \end{tabular} & \
\begin{tabular}{c} **Impulse Ground** \\ **1 (Bar-s)** \\ \end{tabular} &
\begin{tabular}{c} **Impulse Ground** \\ **2 (Bar-s)** \\ \end{tabular} \\ \hline no plate & 0.00103 & 0.00247 & - & 0.001427 & - \\ no plate & 0.00105 & 0.00275 & - & 0.001388 & - \\ no plate & 0.00097 & 0.00261 & - & - & - \\ \hline
2 expanded metal & 0.00108 & 0.00105 & 60 & 0.001384 & 0.002338 \\
2 expanded metal & 0.00108 & 0.00105 & 60 & 0.001287 & 0.002258 \\
2 expanded metal & 0.00105 & 0.00095 & 64 & 0.001127 & 0.001849 \\ \hline
2 expanded metal \& water & 0.00104 & 0.00077 & 71 & 0.001312 & 0.002546 \\
2 expanded metal \& water & 0.00098 & 0.00071 & 73 & 0.001143 & 0.002234 \\ \hline
1 expanded metal & 0.00107 & 0.00155 & 41 & 0.001411 & - \\
1 expanded metal & 0.00100 & 0.00144 & 45 & 0.001395 & - \\
1 expanded metal & 0.00096 & 0.001437 & 45 & 0.001289 & - \\ \hline
1 expanded metal \& water & 0.00094 & 0.00108 & 58 & 0.001418 & - \\
1 expanded metal \& water & 0.00093 & 0.00110 & 58 & 0.001402 & - \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Maximum impulse collected by the three sensors (control, inserted into the wall and laid on the ground) for all experiments. The attenuation of impulse measured on the wall relative to the mean value obtained by the reference tests (no plate) is also given. Impulse ground 1 and impulse ground 2 correspond to the maximum value of the first and the second peak, respectively. Figure 15 presents the overpressure measured by the gauge positioned on the ground at the first plate's position. The reflection of the shock wave, when a plate was placed near this sensor (two-plate configuration), could be observed (see the arrows in the Figure 15). In case of one-plate configurations, the sensor was placed further off the plate and the shock wave reflection was not perceptible. In the case of two-plate configurations, the reflection of the shock wave on the second plate was clearly manifested as a huge overpressure second peak.