An investigation into the effect of biofouling on the ship hydrodynamic characteristics using CFD. (1st March 2019)

• Record Type: Journal Article
• Authors: Song, Soonseok; Demirel, Yigit Kemal; Atlar, Mehmet
• Is Part Of: Ocean engineering. Volume 175(2019)
• Page Start: 122
• Page End: 137
• Publication Date: 2019-03-01
• Subjects: Ship resistance -- Roughness effect -- Biofouling -- Computational fluid dynamics (CFD) -- Full-scale simulation -- KRISO container ship (KCS); Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2019.01.056
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: To reduce the fuel consumption and green-house gas emissions of ships, it is necessary to understand the ship resistance. In this context, understanding the effect of surface roughness on the frictional resistance is of particular importance since the skin friction, which often takes a large portion in ship drag, increases with surface roughness. Although a large number of studies have been carried out since the age of William Froude, understanding the roughness effect is yet challenging due to its unique feature in scaling. In this study, a Computational Fluid Dynamics (CFD) based unsteady Reynolds Averaged Navier-Stokes (RANS) resistance simulation model was developed to predict the effect of barnacle fouling mainly on the resistance and hull wake characteristics of the full-scale KRISO container ship (KCS) hull. Initially, a roughness function model was employed in the wall-function of the CFD software to represent the surface conditions of barnacle fouling. A validation study was carried out involving the model-scale flat plate simulation, and then the same approach was applied in full-scale flat plate simulation and full-scale 3D KCS hull simulation for predicting the effect of barnacle fouling. The increase in frictional resistance due to the different fouling conditions were predicted and compared with the results obtained using the boundary layer similarity law analysis of Granville. Also, a further investigation of the roughness effect on the residuary resistance, viscous pressure resistance and wave making resistance was carried out. Finally, the roughness effect on the wave profile, pressure distribution along the hull, velocity distribution around the hull and wake flows were examined. Highlights: Up to 93% increase in the ship frictional resistance due to the barnacle fouling was observed. Reduced pressure recovery at the stern and increased viscous pressure resistance due to hull fouling were observed. Smaller wave amplitude in the wake region and smaller wave-making resistance due to surface fouling were observed. Increased boundary layer thickness and enlarged wake field due to the hull fouling were observed. Up to 47% increase in nominal wake fraction due to the hull fouling was observed.