## 3 Results of CFD Simulation
The overturning moments are equal to the sum of the moments caused by the masses of the particular parts of the crane jib G1-G4 without the external load but with the aerodynamic force generated by the wind taken into account, as shown in Figure 9. The geometrical dimensions as well as the masses of the structure elements are assumed according to the technical and commissioning documentation [37]. Therefore, it should be noted here that the mentioned parameters are estimated with a certain approximation, and they should not be treated as data provided by the producer. The test object itself is treated as an example for calculating the stability of a low-slewing crane. The schema of the force distribution acting on the studied crane is shown in Figure 9 and Table 4. The aerodynamic forces induced by wind are marked with the symbol W. The values of these forces are determined in the next step of the analysis according to the standard Eurocode for \(\theta\) = 90\({}^{\circ}\)[41], experimental results for \(\theta\) = 0\({}^{\circ}\) and \(\theta\) = \(\pm\)90\({}^{\circ}\)[36], and the results obtained from the CFD simulations for the \(\theta\) range from \(-\)90\({}^{\circ}\) to +90\({}^{\circ}\) with steps equal to 15\({}^{\circ}\)  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline  & \multicolumn{3}{c}{**Urban Terrain**} & \multicolumn{3}{c}{**Village Terrain**} & \multicolumn{3}{c}{**Open Terrain**} \\  & \multicolumn{3}{c}{**v\({}_{\rm ref}\) = 7.03210 [m/s]**} & \multicolumn{3}{c}{**v\({}_{\rm ref}\) = 6.62928 [m/s]**} & \multicolumn{3}{c}{**v\({}_{\rm ref}\) = 6.340482 [m/s]**} \\ \hline \multicolumn{2}{c}{**Angle \(\alpha\)**} & \multicolumn{1}{c}{\({}_{\rm X}\)} & \multicolumn{1}{c}{\({}_{\rm Y}\)} & \multicolumn{1}{c}{\({}_{\rm M}\)} & \multicolumn{1}{c}{\({}_{\rm X}\)} & \multicolumn{1}{c}{\({}_{\rm Y}\)} & \multicolumn{1}{c}{\({}_{\rm M}\)} & \multicolumn{1}{c}{\({}_{\rm X}\)} & \multicolumn{1}{c}{\({}_{\rm Y}\)} & \multicolumn{1}{c}{\({}_{\rm M}\)} \\ \hline
0 & 1.517 & 0.000 & 0.900 & 1.511 & 0.002 & 0.831 & 1.530 & 0.03 & 0.762 \\
15 & 2.077 & \(-\)0.049 & 1.370 & 1.990 & \(-\)0.029 & 1.229 & 1.939 & \(-\)0.005 & 1.095 \\
30 & 2.520 & \(-\)0.295 & 1.733 & 2.395 & \(-\)0.246 & 1.551 & 2.319 & \(-\)0.202 & 1.385 \\
45 & 2.956 & \(-\) \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Overturning Moments from**} & \multicolumn{4}{c}{**Stability Moments from Crane Weights Only**} \\  & \multicolumn{4}{c}{**Crane Weights Only**} & \multicolumn{4}{c}{**\(\Sigma\)M\({}_{\text{S}}\) = 1380.85 kNm**} \\  & \multicolumn{4}{c}{**\(\Sigma\)M\({}_{\text{O}}\) = 1228.90 kNm**} \\ \hline  & \multicolumn{4}{c}{**Jib**} & \multicolumn{4}{c}{**Max Load**} & \multicolumn{4}{c}{**Tower**} & \multicolumn{4}{c}{**Support Base**} \\  & \multicolumn{4}{c}{_load_} & & & & & \\ \hline \(G1\) & \(G2\) & \(G3\) & \(G4\) & \(G5\) & \(Q1\) & & \(G6\) & \(G7\) & \(G8\) \\ \hline
130 & 330 & 1440 & 1440 & 200 & 3050 & kg & 7600 & 7660 & 26,000 \\
1275 & 3237 & 14,126 & 14,126 & 1962 & 29,921 & N & 74,556 & 75,145 & 255,060 \\ \hline \multicolumn{8}{c}{_distance from the tipping line_} \\ \hline \(r1\) & \(r2\) & \(r3\) & \(r4\) & \(r5\) & \(rQ5\) & & \(r6\) & \(r7\) & \(r8\) \\ \hline
39 & 33 & 22 & 6 & 21 & 21 & m & 0.87 & 2.10 & 4.54 \\ \hline \multicolumn{8}{c}{_moments_} \\ \hline \(M1\) & \(M2\) & \(M3\) & \(M4\) & \(M5\) & \(M_{\text{Q}}5\) & & \(M6\) & \(M7\) & \(M8\) \\ \hline
49.17 & 106.75 & 313.54 & 88.52 & 41.29 & 629.63 & kNm & 64.67 & 157.80 & 1158.38 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Selected geometrical dimensions of the Liebherr 63 K crane and the values of moments used for calculations. The maximum load weight at a height of 21 m is 3050 kg [41]. Figure 9: The distribution of loads acting on the 63 K crane, which was considered in the calculations according to Eurocode (\(\theta\) = 90\({}^{\circ}\)).