Experimental determination of added resistance due to barnacle fouling on ships by using 3D printed barnacles

3D printed artificial barnacles were attached on flat plates and towed over a range of Reynolds numbers in order to be able to calculate added resistance and power requirements of ships due to calcareous fouling. Since barnacle fouling occurs naturally it is possible to observe the barnacles in different sizes on any randomly selected ship surface. To model this condition three different barnacle sizes were selected and used to represent growing stages of the attached barnacles. The flat plates were covered with barnacles within a range of 10% to 50% area coverage respectively and towed over different speeds at the Kelvin Hydrodynamics Laboratory in the University of Strathclyde. Frictional resistance coefficients and roughness function values were then calculated for each surface based on experimental results. Roughness effects of the given fouling conditions on the frictional resistances were then predicted for a bulk carrier ship using an in-house code developed based on boundary layer similarity law analysis. Added resistance diagrams were plotted using these predictions. Finally, the increase in the frictional resistance and powering penalties of the ship were predicted using the generated diagrams.