Experimental Study of Wave Loading by Internal Solitary Waves on a Semi-Submersible Platform

Abstract

The experimental measurements presented here describe the major features of the loads exerted by internal solitary waves (ISWs) on columns and caissons of a semi-submersible platform in a two-layer fluid system. Particular attention is paid on the forces acted on the platform under different layer thickness ratio. By use of the dynamometer for forces of three degree of freedom (DOF), the wave forces exerted by the ISWs on the columns and caissons of the model are measured quantificationally, so the variations of forces with ISW’s amplitude and upper layer depth are derived. Comparisons are made between the experimental results and calculations based on the modified Morison equation and pressure integral method. The calculated results are well consistent with the measurements, so the method is capable of providing satisfactory predictions on the forces. Besides, the results show that the wave height has a considerable influence on the wave loads produced by the ISWs, and the forces varies with the different locations of the interface between the upper and lower layer.