Experimental evaluation of energy transmission coefficient for step floating breakwaters

In the current study، the step floating breakwaters were under consideration to improve the π type floating breakwater performance. By means of physical modeling 180 experiments were carried out in the wave flume for different geometric and hydrodynamic parameters including 2 and 3 step FBs. Result were then compared with standard π type FB with the same width. To be able to compare experimental results، kHi50 (which is an incident wave characteristics with transmission coefficient less than 0. 5) was introduced. Results obtained through this study show that using step floating breakwater can be enhanced the hydrodynamic performance as well as reducing the construction material. In addition by increasing the width of steps، FBs performance was improved. Comparison of 2 and 3 step floating breakwaters reveal that the performance of each type is dependent on the draft depth. However it can be concluded that with increasing the step width، the difference of their performance is decreased.