Hydro-morphological investigations on local scour around inclined piles under wave conditions

Scouring is a problem that should be considered while designing bridges; scour around inclined piles in the presence of waves has rarely been researched. However, in reality, many inclined braces are used for aesthetic reasons, which alters the flow properties depending on their exposure to the flow field. The purpose of this work is to numerically examine the flow behavior and local scour evolution around inclined piles downstream under wave conditions. The effect of three inclination angles (10°, 20° and 30° downstream flow direction) is numerically investigated compared with the vertical circular pile. A three-dimensional hydro-morphological turbulent model is used. The reliability of the flow and scour estimates was verified with remarkable accuracy. The results reveal that the inclination affects both the intensity and location of the downflow, as well as the pattern of the horseshoe vortex upstream of the pile. Vertical piles have deeper scour than inclined ones, owing to the decrease of downflow in front. Strong horseshoe vortices arise upstream of inclined pier scouring variance patterns between inclined piles and vertical piles. The scour reduction increases with increasing the inclination angle. The Keulegan-Carpenter number (KC) has a slight effect on the scour reduction due to the three-inclination angle. The scour reduction due to the inclination with wave conditions is lower than the reduction at current conditions.