LOCAL SCOUR AROUND A LARGE-SCALE VERTICAL CIRCULAR CYLINDER DUE TO COMBINED WAVE-CURRENT ACTION

The local scour around a large -scale vertical circular cylinder due to combined wave-current action was experimentally and numerically studied in the present paper. Experiments were carried out to research the affect of the wave height, current velocity and the diameter of the cylinder on the scour process. The topography near the cylinder in various cases during scour was measured. The cylinder diameter affects the distribution of scour and deposition area. The maximum scour depth increases evidently when the current velocity increases. The maximum scour depth does not increase after the wave height retains a certain value. A numerical model using a finite element method for simulating the scour process was established. And the numerical results agree well with the measured data. The numerical model is more applicable in the case of large-scale cylinders.