Experimental study of surface roughness effects on hydrodynamic characteristics of a submerged floating tunnel

Marine biofouling is a major concern in the operational performance of submerged floating tunnels (SFTs). The objective this research to investigate effects marine fouling (represented by surface roughness) on hydrodynamic behavior SFTs, including forces SFT subject current-only, wave-only, and combined current-wave flow conditions. increased roughness induced dynamic response an are characterized force coefficients, drag inertia coefficients. At Water Lab Delft University Technology (TU Delft), experiments have been performed wave-current flume compare SFTs’ behaviors as affected different characteristics. In addition, parametric cross-section for presented, associated with shape circular compared. results show that can effectively reduce coefficient (Cd) under current-only conditions lower (Cm) when waves present. As height coverage ratio increase, Cd generally increases while Cm decreases. However, small differences be observed regard parameters wave-only Morison coefficients adapted marine-fouled measured compared predictions from engineering standards recommended practice.