## 3 Results
### Experimental Results
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Angle \(\beta\) (\({}^{\circ}\))** & \(\mathbf{F_{X}}\) **(N)** & \(\mathbf{F_{Y}}\) **(N)** & \(\mathbf{M_{Z}}\) **(Nm)** \\ \hline
0 & 5.580 & 0.021 & 1.079 \\
15 & 4.769 & 1.332 & 0.214 \\
30 & 4.579 & 0.474 & 0.688 \\
45 & 5.103 & 0.283 & 0.645 \\
60 & 4.865 & 0.307 & 0.704 \\
75 & 4.221 & \(-\)0.409 & 0.293 \\
90 & 3.863 & 0.378 & 0.625 \\
105 & 4.078 & 1.022 & 0.685 \\
120 & 5.032 & 0.021 & 0.790 \\
135 & 5.294 & \(-\)0.146 & 0.471 \\
150 & 5.008 & \(-\)0.337 & 1.116 \\
165 & 4.793 & \(-\)1.267 & 0.253 \\
180 & 4.984 & \(-\)0.099 & 0.661 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Experimental results obtained for jib truss model with “quasi-laminar” airflow. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Angle \(\beta\) (\({}^{\circ}\))** & \(\mathbf{F_{X}}\) **(N)** & \(\mathbf{F_{Y}}\) **(N)** & \(\mathbf{M_{Z}}\) **(Nm)** \\ \hline
0 & 7.822 & \(-\)0.671 & 0.299 \\
15 & 6.963 & 0.665 & 0.504 \\
30 & 6.725 & \(-\)0. Figure 16: Average speed and speed from the thermo-anemometer measured every 5 s for turbulent airflow and wind direction \(\beta=0^{\circ}\) (tower truss model). Figure 17: Average speed and speed from the thermo-anemometer measured every 5 s for “quasi-laminar” airflow and wind direction \(\beta=0^{\circ}\) (jib truss model). Figure 18: Average speed and speed from the thermo-anemometer measured every 5 s for turbulent airflow and wind direction \(\beta=0^{\circ}\) (jib truss model). Figure 15: Average speed and speed from the thermo-anemometer measured every 5 s for “quasi-laminar” airflow and wind direction \(\beta=0^{\circ}\) (tower truss model). The average errors \(\epsilon_{\text{AVG}}\) for coefficient \(\text{C}_{\text{X}}\) for all investigated cases are shown in Table 10. These values were estimated according to the following formula:  
\[\epsilon_{AVG}=\frac{\sum_{i=1}^{n}\left|\frac{\text{C}_{X}^{EXP-\text{C}_{X}^{ NUM}}}{\text{C}_{X}^{NUM}}\right|}{n}, \tag{8}\]  
where \(\text{C}_{X}^{\text{EXP}}\) and \(\text{C}_{X}^{\text{NUM}}\) are the aerodynamic coefficients obtained from the experiment and numerical simulation, respectively. It seems that the results of the numerical simulation slightly overestimate the value of the aerodynamic force \(\text{F}_{\text{X}}\), which plays an important role when the tip-over of the tower crane could happen. Moreover, the best match was obtained for the tower crane model in the case of turbulent flow. Finally, it is worth noting that in the case of the force coefficient \(\text{C}_{\text{Y}}\), the results from the experimental tests and numerical simulations reveal noticeably worse agreement in comparison with those of the \(\text{C}_{\text{X}}\) coefficients. This could be explained by the fact that the \(\text{F}_{\text{Y}}\) force component had values that are close to zero. Thus, it was measured during the experiment with a relatively large error. Example distributions of the static pressure are shown in Figures 3b and 5b. Here, it is worth noting that a better convergence of the numerical solution is observed in the case of turbulent flow. In this case, the number of iterations was not more than about 50, whereas in the case of \"quasi-laminar\" airflow, the total number of iterations was more than 80. Moreover, the main problem relates to the continuity criterion.