Pressure field in skimming flow over a stepped spillway

The purpose of this work is to characterize the pressure field of the skimming flow over a stepped spillway. The pressure is measured using a piezo-resistive transducer. In order to carry out this experimental work, a physical model of a stepped spillway was built. The pressure field will be shown from two points of view: its evolution along the spillway will be measured at the centre of symmetry of the steps, on both vertical and horizontal faces. Also, the mean, maximum and minimum pressure patterns on the horizontal and vertical faces of a step will be presented. According to the value of the pressures, two different areas will be described in each case: a zone in which the flow exerts impact (high pressures) and a zone characterized by the existence of negative pressures. The main conclusions obtained through image processing for fluid dynamics are also shown. This technique consists in recording the flow over a spillway with a video camera. The recorded sequences are digitized and processed by means of the software package DigImage. This methodology allows to make a qualitative estimation of several aspects of the entrapped wakes under the skimming flow.