ROUGH TURBULENT BOUNDARY LAYER IN WAVE-CURRENT COMBINED MOTION

Abstract

Experimental and numerical investigations are carried out for waves with following and opposing currents. The flume bottom is covered by triangular strip roughnesses. The K-ε model is solved, for the large Reynolds number flow, with the Galerkin finite element method. Profiles and time series of the ensembleaveraged horizontal velocity are well predicted except in the very vicinity of the bottom. Magnitude but phase of the r. m. s. velocity fluctuations is reasonable predicted. Time-mean horizontal velocity and r. m. s. horizontal velocity fluctuation are also well predicted. The measured data give a much smaller von Karman constant which is not predicted by the model.