HYDRODYNAMIC FORCES ON ROUGHENED HORIZONTAL CYLINDERS

Experimental results on hydrodynamic forces are presented for three slender horizontal cylinders, each with a different surface roughness: sand-roughened, barnacle-roughened and rigid artificial sea anemones. These cylinders were tested in periodic waves and in periodic waves plus steady towing with Reynolds numbers up to 5 x 10E5. Hydrodynamic forces were studied based on the Morison equation and the harmonic analysis. Forces on cylinders under periodic waves only and under waves and towing were analysed and compared. The surface roughness effects on forces were examined.