Sammendrag
Effect of roughness on frictional resistance is investigated experimentally and numerically. Resistance
tests are performed with several plates coated with different paints, which have different roughness.
Front plate is 4 m long and aft plates are 6 m long resulting in a total hydrodynamic length of 10 m.
Tests are conducted at different speeds up to 9 m/s covering a large range of Reynolds numbers.
Numerical calculation of frictional resistance is performed for the same roughness as tested in the
towing tank. Special wall function and numerical procedure is implemented for this purpose. Plates
are 3D scanned and their roughness is categorized by several parameters, not only traditional
roughness height. Numerical and experimental results are compared and discussed.
tests are performed with several plates coated with different paints, which have different roughness.
Front plate is 4 m long and aft plates are 6 m long resulting in a total hydrodynamic length of 10 m.
Tests are conducted at different speeds up to 9 m/s covering a large range of Reynolds numbers.
Numerical calculation of frictional resistance is performed for the same roughness as tested in the
towing tank. Special wall function and numerical procedure is implemented for this purpose. Plates
are 3D scanned and their roughness is categorized by several parameters, not only traditional
roughness height. Numerical and experimental results are compared and discussed.