Author(s): A. Armanini; M. Righetti; F. Sartori
Linked Author(s): Aronne Armanini
Keywords: No Keywords
Abstract: In this paper we analyze the problem of scourings and depositions in the proximity of a groyne system. The investigation is based on the results of an experimental investigation on scale model. The bed material adopted in the model consists of light plastic material. The experimental analysis has shown the formation of a bar between two consecutive groynes. In order to explain the mechanism of formation of such a bar, we measured the flow field with a3D Micro acoustic Doppler velocimeter. We have observed that the direction of the secondary circulation depends on the curvature of the path lines. Moreover, the formation of the bar is likely related to the suspended load. The secondary circulation inside the hole downstream the groyne is clockwise oriented and the material is whipped up by the longitudinal vortex responsible for the local scouring. The distribution of Reynolds stress in a horizontal plane confirms the mechanism.