Author(s): Robert Ljubicic; Budo Zindovic; Filip Djordjevic; Radomir Kapor; Ljubodrag Savic
Linked Author(s): Radomir Kapor, Budo Zindovic
Keywords: Hydraulic jump stilling basin image velocimetry camer
Abstract: Hydraulic jumps play an essential role in ensuring dam safety, providing a mechanism for efficient dissipation of excess water energy. In such cases, a common design strategy includes physical modeling to ensure that the occurring jump meets the required efficiency parameters in terms of the resulting flow depths and velocities. Such modeling often involves measurement techniques which are often time consuming and/or are limited to a small number of points, resulting in a limited depiction of the jump's overall behavior. Furthermore, many conventional techniques require direct contact with the flowing water, which effectively interferes with measured quantities. To gain a more comprehensive understanding of this phenomenon, we developed and tested a contactless method for estimating the hydraulic jump residual energy by analyzing flow velocity profiles immediately downstream of the jump roller using camera-based measuring technique based on particle image velocimetry (PIV). This technique enables the collection of instantaneous and time-resolved longitudinal 2D velocity fields, providing a more detailed look into the hydraulic jump effects which propagate downstream of the stilling basin. The described method was tested in a laboratory setting with both unbaffled and baffled stepped spillway stilling basins. In the case of baffled basins, various baffle sizes and positions were investigated, and the resulting downstream velocity profiles were compared to estimate the efficiency of their respective jumps using factors such as the velocity distribution, Coriolis coefficient, relative temporal variance, and the Q criterion for vorticity. The results indicate that camera-based techniques can help provide a better understanding of the hydraulic jump behavior and can significantly complement the conventional measurement methodologies by allowing access to previously unavailable metrics which play a vital role in the characterization of the hydraulic jumps.
Year: 2025