Skin Friction Measurements in Flows Over Tethered Polymer Coatings

The effect of a tethered polymer coating on the turbulence production in a turbulent boundary layer was examined. An experimental investigation was carried out in the Naval Ocean Systems Center (NOSC) water tunnel. The aims of the study were to determine the existence of an interaction between the tethered polymer coating and turbulence production at the wall and in the outer layer. Skin friction was measured in a flat plate turbulent boundary layer with and without tethered polymer coating. There were no measurable effects on the turbulent boundary layer skin friction. We should point out the purpose of the tethered polymer coatings is the prevention of biofouling on ships. With this fact in mind it is encouraging that the coating has no deleterious effect on the boundary layer.