Wind tunnel experiment and numerical analysis for current load acting on semi-submersible platform

Abstract

In this study, the current loads acting on a semi-submersible was measured in the wind tunnel. To obtain the uniform flow which resembled current flow, the top of the model face down to the floor of a wind tunnel. But this installation method cannot ensure the uniform flow because of the floor and generate the boundary layer on the floor. To decrease or eliminate the boundary layer, new experimental equipment was designed and this is height adjustable from the floor. The vertical velocity profiles and current loads were measured for various height and the height was found to give the converged velocity profile and current load. And numerical simulation was performed by using CFD method. From the numerical analysis, the computational conditions such as domain size, boundary condition, grid system, and computational scheme had been inferred. And the interference computational condition can be applied to a prediction of the current load acting on offshore structures.