A methodology for digitizing and processing calcareous biofouling typically found on US Navy ship hulls has been developed. Panels that were immersed in seawater and allowed to grow biofouling were captured using 3-D laser scanning. The advantage of these digital replicas over real biofouled rough surfaces are many-fold: the surfaces can be manipulated to meet channel flow and large eddy simulation (LES) viscous size constraints; 3-D printing can then be used to build scaled rough surfaces that can be used in the fully developed turbulent channel flow; complex statistical and geometric parameters that encapsulate drag-producing physics can be computed; subregions of the surfaces can be tiled together to create composite surfaces that can span various parameter spaces. This paper describes, in detail, the digitizing, surface preparation, and 3-D printing methodologies. In addition, it describes the surface characterization software. Data from nine scanned surfaces, with biofouling from coastal Florida and Pearl Harbor, Hawaii are shown with preliminary correlations between pierside data and more complex geometric parameters. The work described herein is part of a larger project to develop a fast and accurate ReynoldsAveraged Navier Stokes (RANS) computational fluid dynamics (CFD) method to predict the drag penalty of fouled ships based on data obtained from pierside underwater surveys.

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