Experimental and numerical study of wave loads on an open-bottom cylinder in open and icy waters

Offshore structures in polar regions experience loads from ice, waves, currents, and wind. However, the extreme combined loads on these structures cannot be predicted accurately due to our limited physical comprehension of the fluid-ice-structure interaction. To address this knowledge gap, two laboratory experiments were conducted to explore the interactions between waves, ice floes, and an open-bottom cylinder. In one test series, the ice tank was filled with saline water, while in the other, it contained ice-covered saline water. To investigate the change of wave loads between open-water and ice-covered conditions, the same set of regular waves with varying periods and heights was generated for the two test series. When analyzing the collected measurements, several data analysis techniques were employed. Experimental results show that the wave loads in icy waters are reduced by an average of 14% and up to 26% compared to the open-water scenario. This decrease stems primarily from wave attenuation. Additionally, two potential flow methods and a commercial program were applied to predict wave loads. Numerically obtained results by these approaches are very similar and satisfactory for the open-water case (mean normalized error is 7% in comparison to measurements), but the error nearly triples (20.2%) for the ice-covered waters.