Recently, the demand for floating solar power farms in lakes and coasts (rather than on land) has been increasing rapidly. It is important to develop a numerical analysis technique that considers environmental conditions to predict structural stability and accurate motion response while designing a floating solar power farm. In this study, we performed a comparison under conditions similar to those of the Inha University towing tank (IUTT) model test to verify the numerical analysis method. The results revealed that heave and pitch movements were dominant under head sea conditions. Relative behavior occurred because of the hinge connection of each unit, and complex motion characteristics appeared depending on the wave conditions. The numerical method was verified based on the motion response and load of the floating solar farm. The validity of the results was also confirmed.

Accurate resistance performance evaluation is essential to predict the minimum propulsion horsepower required for ships in real sea. Therefore, in this paper, the added resistance performance of K-Supramax in various wave conditions was calculated using CFD (Computational Fluid Dynamics). First, to compare the resistance performance according to the DOF (Degree of Freedom), the added resistance performance in the head regular wave was investigated and compared with the experiment. The 2DOF and 6DOF results in the head regular wave had no significant differences. Second, to compare the resistance performance among various wave conditions, the effect of the heading angle was analyzed by comparing resistance and motion RAOs (Response Amplitude Operators) in bow quartering sea conditions using 6DOF. The added resistance showed the highest value near the resonance frequency of 170°. As the heading angle increased, the added resistance tended to decrease, regardless of the wavelength ratio. Also, the added resistance performance in irregular waves was investigated with reference to the adverse conditions. The spectral method, which linearly superimposes regular wave results, and the added resistance generated during irregular waves directly through CFD were compared. The resistance in irregular waves increased by approximately 92% for the spectral method and by approximately 72% for the direct irregular wave calculation compared to the resistance in calm water. In addition, the PSD (Power Spectral Density) of resistance and the distribution of motion RAOs obtained from direct irregular wave calculations were investigated.

In the present study, we investigated planing forces of supercavitated bodies by using the supercavitation shape produced by the disk type cavitator. The cavity shapes are observed to find the immersion draft and planing angle when the stern of the supercavitated body is partially immersed in the water. To make the planing the angle-of-attack (AOA) of the supercavitated body is varied statically against the main flow and the planing tests are carried out for different body shapes that are changed systematically. The drag, lift and pitch moment acting on the body are measured to understand the relation between the planing force and the immersion draft of the supercavitated body. It is found that the planing force increased in general linearly with the immersion draft ratio and the planing angle is certainly not proportional to the immersion draft ratio.