Air Entrainment and Free Surface Modeling of Fully Turbulent Flow Near the Broad-Crested Weirs

The research was carried out at the Department of Hydraulic Engineering, Faculty of Civil Engineering, Slovak University of Technology in Bratislava with close cooperation with Institute of Water Structures, Faculty of Civil Engineering, Brno University of Technology. One of the important goals was the determination of the most accurate approach related to the computational fluid dynamics modeling of the air-water interaction. Research consists of two main research methods to ensure the accuracy, set up the possibilities of cooperation and the results control. The first method was the physical model of broad-crested weir installed in collapsible canal in hydraulic laboratory and the second was numerical computational fluid dynamics model of broad-crested weir created in same scale. In free surface flows the air entrainment phenomena plays an important role. Air entrainment is affecting the volume fraction, velocity field, energy dissipation and many other parameters related to dynamic behavior of water near the crests. Different approaches were carried out to identify most accurate computational fluid dynamics setup compared to physical model measurements. Compared results and the accuracy assessment are summarized and the best computational fluid dynamics parameterization is recommended