Extreme pressure forecasting methodology for the hydraulic jump downstream of a low head spillway

Abstract

Extreme pressures in the hydraulic jump are associated with risk of damage to the flow discharge system of dams by a series of mechanisms. Therefore, understanding and predicting these efforts are crucial for the safe and economical design of discharge systems. Thus, this paper aims to validate an existing pressure forecasting methodology for estimating the extreme pressure in the hydraulic jump with low Froude number (below 4.5). Results have shown that the method may be used for this situation on a preliminary basis. Further studies are recommended to refine the technique and to achieve results that are more precise.

Analysis of hydraulic parameters in determining the occurrence of cavitation in the spillways of the Furnas, Luiz Carlos Barreto de Carvalho and Batalha hydroelectric power plants

“…The occurrence of severe damage was associated with V > 40.0-45.0 m/s and σ ≤ 0.17. Novakoski et al (2017), Hampe et al (2020), Mousavi et al (2020a, 2020b) and Steinke Junior et al (2021 performed similar analyses in stilling basins observing pressure fluctuations in scaled down physical models and their effects at prototype scale.…”

“…In hydraulic structures such as spillways and stilling basins, responsible for the safety of dam integrity, the phenomenon of cavitation is widely studied since its hydrodynamic efforts, originating in turbulent flows and characterized by high velocity flows and high complexity, may generate cumulative and irreversible damage to the surfaces of the lining of these devices (Colgate, 1977;Falvey, 1990;Bhate et al, 2021;Schleiss et al, 2023). Cavitation is defined as the formation and later collapse of bubbles of vapor, water or different gases dissolved in the fluid, by the brusquely diminished pressure and significant increase of flow velocity (Pinto et al, 1988;Quintela & Ramos, 1980;Tullis, 1982;Bhate et al, 2021;Hampe et al, 2020;Mortensen, 2020).…”

“…Many scale model studies and damage analysis at prototype scale attribute the damage generated by the phenomenon of cavitation and/or erosion in hydraulic structures to maximum velocities and minimal extreme instantaneous pressures (Bhate et al, 2021;Matos et al, 2022;Schleiss et al, 2023). Lopardo (1996Lopardo ( , 2013, Hampe et al (2020), Mousavi et al (2020a, 2020b) and Steinke Junior et al (2021 recommends the analysis of pressures with a 0.1% probability of non-exceedance to look at tendencies to cavitation in structures submitted to macroturbulent flows at high velocities. Sanagiotto (2003), Amador et al (2009), Conterato et al (2015), Dai Prá et al (2016, Osmar et al (2018), Canellas (2020), Priebe et al (2021 and Matos et al (2022) analyzed minimum extreme pressures in stepped spillway chutes considering differents ranges of specific discharges, chutes with a slope and step widths.…”

A Novel Comparative Statistical and Experimental Modeling of Pressure Field in Free Jumps along the Apron of USBR Type I and II Dissipation Basins

“…Macián-Pérez et al [21] used a numerical model to analyze pressure distributions in a USBR Type II dissipation basin. Hampe et al [22] estimated extreme pressures in hydraulic jumps with low Froude numbers. Samadi et al [23] used some explicit data-driven approaches to estimate the C P coefficient underneath hydraulic jumps on a sloping channel.…”