# Study of the Interaction between Regular Waves and a Wind-Fish Combined Structure
## 3 Results
### Other Influencing Factors  
As a permeable structure, long-term exposure to the marine environment and the attachment of marine organisms will also threaten the safety of the composite structure. Therefore, this paper studies the influence of different cage submergence depths and different degrees of attachment of marine organisms on the load on the combined structure. The degree of attachment of marine organisms mainly corresponds to different cage densities. In this paper, seven different cage submergence depths and two cage densities are set, and the specific design parameters are shown in Table 5. The wave height is 0.12 m, the period is 1.4 s, and the water depth is 1 m.  
As can be seen from Figures 12 and 13, with the increase in the diving depth of the cage, the horizontal wave load on the combined structure shows little change. The increase \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Case No.**} & \multirow{2}{*}{\begin{tabular}{c} **Height of Cage** \\ **(m)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Diameter of** \\ **Cage (m)** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Solidity of Cage** \\ **(m)** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Subergence** \\ **Depth (m)** \\ \end{tabular} } \\ \hline
16 & 0.5 & 2.0 & 0.27 & 0.00 \\
17 & 0.5 & 2.0 & 0.27 & 0.04 \\
18 & 0.5 & 2.0 & 0.27 & 0.06 \\
19 & 0.5 & 2.0 & 0.27 & 0.08 \\
20 & 0.5 & 2.0 & 0.27 & 0.30 \\
21 & 0.5 & 2.0 & 0.27 & 0.60 \\
22 & 0.5 & 2.0 & 0.27 & 0.90 \\
23 & 0.5 & 2.0 & 0.13 & 0.00 \\ \hline \hline \end{tabular} Note: (1) Cases No. 16–22 mainly explore the influence of cage submergence depth on the load on the combined structure and individual structure. (2) Cases No. 16 and 23 mainly explore the influence of cage compactness on the load on combined structures and individual structures.  
\end{table} 
Table 5: Parameters of other influencing factors. Figure 11: Hydrodynamic load distribution of the combined structure under different cage heights (**a**) and diameters (**b**). in the density of the cage will lead to an increase in the effective area; afterwards, the horizontal wave load on the combined structure will also increase. The load on the combined composite structure is still dominated by the inertial force, with a weak drag force. Table 6 and Figure 14 indicate the proportion of the maximum horizontal load on the wind turbine foundation under different submergence depths and cage plugging rates. The results portray that the proportion of the maximum horizontal load on offshore wind turbines gradually increases from 93.05% to 99.78% with the increase in the diving depth of the cage, indicating that the wave-blocking effect of the cage on the wind turbine foundation becomes weaker and weaker. However, with the increase in the degree of adhesion of marine organisms, the proportion of the maximum horizontal load on the offshore wind turbine decreases from 97.35% to 93.05%, demonstrating that increased adhesion of marine organisms increases the wave resistance of the cage. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Case No.** & \begin{tabular}{c} **Wind Turbine** \\ **Foundation Load (N)** \\ \end{tabular} & \
\begin{tabular}{c} **Cage Load** \\ **(N)** \\ \end{tabular} &
\begin{tabular}{c} **Proportion of Wind** \\ **Turbine Load** \\ \end{tabular} \\ \hline  & 16 & 24.91 & 1.86 & 93.05\% \\  & 17 & 26.66 & 1.67 & 94.11\% \\ Different & 18 & 26.62 & 1.59 & 94.36\% \\ submergence & 19 & 26.71 & 1.45 & 94.85\% \\ depths & 20 & 26.74 & 0.81 & 97.05\% \\  & 21 & 26.72 & 0.17 & 99.36\% \\  & 22 & 26.68 & 0.06 & 99.78\% \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Distribution and proportion of the maximum horizontal load on the combined structure caused by different cage submergence depths and cage plugging rates. Figure 12: Load duration curve and spectrum of the combined structure under different cage submergence depths. (**a**) Time domain curve. (**b**) Frequency domain diagram.