On validation of multi-level method for simulation of flow around a mega-float: Comparison of numerical calculation with model experiment

A multi-level model for the calculation of tidal flow and material diffusion of a bay has been developed to simulate ocean environmental problems. Recently, it has been extended to the problem of a bay with a very large floating structure or a mega-float. However, the validation of the application is required before the model can be generalized, because the multi-level model is based on a quasi-three dimensional method with hydrostatic pressure approximation. In this paper, results of a model experiment are compared with those of numerical calculations and the applicability of multi-level model is discussed. In the model experiments, the flow around a towed pontoon was measured. The draft was changed to investigate the effect of draft/water depth ratio, and the mass-flux below a pontoon was estimated from the measured velocity profile. Then measured distributions of velocity and mass-flux below the pontoon are compared with calculations by a multi-level model in which the existence of a mega-float is taken into account.