Investigating roughness effects on ship resistance in shallow waters

Shallow waters influence the behaviour and performance of a vessel by modifying local pressure distribution, wave making, boundary layer thickness. The thickness is also influenced surface roughness. No previous studies have investigated combined effects shallow water contributions roughness on ship resistance. This study aims to fill this knowledge gap in literature using Unsteady Reynolds Averaged Navier-Stokes modelling. Results show that total resistance coefficient increases between approximately 22% 36% presence depending speed depth-to-draft ratio. numerical model used shows grows at faster pace than frictional its relative contribution when applied, contrary deep cases.