BED SHEAR-STRESS MEASUREMENTS OVER A SMOOTH BED IN 3-DIMENSIONAL WAVE-CURRENT MOTION

Wave and current experiments have been carried out with the purpose of measuring the instantaneous bed shear stress over a hydraulically smo oth bed in order to evaluate the extent of the interaction. Measuremen ts have been carried out with a dual-component hot-film probe which, w ith some constraints, enables the magnitude and direction of the insta ntaneous bed shear stress to be measured. Results are presented as max imum obtained bed shear stress values over one cycle and the correspon ding mean value in the direction of the current for various combinatio ns of waves and current.