On dam-break wave propagation and its implication to sediment erosion

Hsu, Hung-Chu; Torres-Freyermuth, Alec; Hsu, Tian‐Jian; Hwung, Hwung-Hweng; Kuo, Ping-Chiao

doi:10.1080/00221686.2013.857365

Cited by 13 publications

(13 citation statements)

References 36 publications

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“…Twelve different scenarios of simulations were tested by combining different upstream water levels (M) of the reservoir (0.10, 0.20 and 0.40 m), and downstream water levels (J) in the flume (0, 0.02, 0.04 and 0.08 m). As mentioned, the ratio (r) of downstream (J) and upstream (M) water depths was used as the scaling, non-dimensional parameter (Equation 2) (Stansby et al, 1998;Jánosi et al, 2004;Bukreev & Gusev, 2005;Hsu et al, 2014):…”

Section: Experimental Planningmentioning

confidence: 99%

“…The classification, generation and propagation of dambreak waves define the evolution of the phenomenon, principally the impacts and consequences of the flow in downstream locations. Over the years, experimental observations and measurements aided the characterization of flows in their initial stages and the temporal and spatial evolution, including jet types, wave height, water level changes (peaks), and the relevant kinematic parameters such as wave front velocity, acceleration or deceleration (Stansby et al, 1998;Jánosi et al, 2004;Bukreev & Gusev, 2005;Leal et al, 2006;Soares-Frazão & Zech, 2007, 2008Ozmen-Cagatay & Kocaman, 2010;Khankandi et al, 2012;Hsu et al, 2014;Elkholy et al, 2016;Liu & Liu, 2017;Espartel, 2015;Stolle et al, 2019;Von Häfen et al, 2019). However, experimental data are lacking in the literature combining jet flows and break shapes, including maximum values of dam-break waves with spatial and temporal evolution.…”

Section: Introductionmentioning

confidence: 99%

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Experiments on initial stages of development of dam-break waves

Espartel

Manica

2021

RBRH

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The initial stages of instantaneous dam-break waves are here evaluated spatially and temporally through 36 physical experiments. Different conditions were tested for downstream (J) and upstream (M) water depths and their ratios (r) to approach realistic conditions for prototype dams. Two non-dimensional parameters are proposed – effective height (HEF) and effective velocity (VEF) – to evaluate water depths and velocity peaks along the dam-break wave evolution. The maximum wave height is estimated as a function of r, whereas the HEF is inversely related to r. The maximum VEF peak is registered for r between 0.1 and 0.2, considered a critical description for real dams. The presence of downstream water depth also modifies the dam-break wave frontal shape and types of wave break features. Previously published classifications of the moving wave based on those features are now expanded with a first tested r = 0.8 in which no jet was identified (undulated movement).

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Section: Experimental Planningmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experiments on initial stages of development of dam-break waves

Espartel

Manica

2021

RBRH

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“…The initial water height of the reservoir is primarily responsible for the scattering of experimental results [15]. The wave front velocity increases with decreasing water depth ratio before and after the gate [16]. With a wet-bed downstream condition, water leaps are formed downstream of the gate [17].…”

Section: Introductionmentioning

confidence: 99%

“…The removal time in their experiment was estimated to be between 0.06 and 0.08 s, thus confirming that their dam-break test satisfied the criteria. Hsu et al [16] used an automatic gate system with an air compressor, which enabled them to uplift the gate at a constant speed of approximately 1.5 m/s. Ritter [11] derived the theory of the dam-break problem based on simplified Saint-Venant equations, excluding the effects of frictional and turbulent resistance.…”

Section: Introductionmentioning

confidence: 99%

Stochastic Uncertainty in a Dam-Break Experiment with Varying Gate Speeds

Takagi

Furukawa

2021

JMSE

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Uncertainties inherent in gate-opening speeds are rarely studied in dam-break flow experiments due to the laborious experimental procedures required. For the stochastic analysis of these mechanisms, this study involved 290 flow tests performed in a dam-break flume via varying gate speeds between 0.20 and 2.50 m/s; four pressure sensors embedded in the flume bed recorded high-frequency bottom pressures. The obtained data were processed to determine the statistical relationships between gate speed and maximum pressure. The correlations between them were found to be particularly significant at the sensors nearest to the gate (Ch1) and farthest from the gate (Ch4), with a Pearson’s coefficient r of 0.671 and −0.524, respectively. The interquartile range (IQR) suggests that the statistical variability of maximum pressure is the largest at Ch1 and smallest at Ch4. When the gate is opened faster, a higher pressure with greater uncertainty occurs near the gate. However, both the pressure magnitude and the uncertainty decrease as the dam-break flow propagates downstream. The maximum pressure appears within long-period surge-pressure phases; however, instances considered as statistical outliers appear within short and impulsive pressure phases. A few unique phenomena, which could cause significant bottom pressure variability, were also identified through visual analyses using high-speed camera images. For example, an explosive water jet increases the vertical acceleration immediately after the gate is lifted, thereby retarding dam-break flow propagation. Owing to the existence of sidewalls, two edge waves were generated, which behaved similarly to ship wakes, causing a strong horizontal mixture of the water flow.

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“…It was seen that the model application for the study of sediment transport processes was inadequate. Hsu et al [38] presented an experimental and numerical investigation of dam-break driven flow over a horizontal smooth bed for different downstream-to-upstream water depth ratio. The numerical model COBRAS [39,40] based on the 2D vertical RANS equations, with a ke turbulence closure was adopted to simulate the complex hydrodynamics induced by dam-breaking.…”

Section: Introductionmentioning

confidence: 99%

Effects of initial stage of dam-break flows on sediment transport

2018

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Experimental and numerical studies of dam-break flows over sediment bed under dry and wet downstream conditions are investigated and their effects on sediment transport and bed change on flow are illustrated. Dam-break waves are generated by suddenly lifting a gate inside the flume for three different upstream reservoir heads. The flow characteristics are detected by employing simple and economical measuring technique. The numerical model solves the two-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations with k-e turbulence closure using the explicit finite volume method on adaptive, non-staggered grid. The model is validated with laboratory data and is extended for simulating non-equilibrium sediment transport and bed evolution process. The volume of fluid technique is used to track the evolution of the free surface, satisfying the advection equation. The comparison study reveals that the current model is capable of defining the dam-break flow and improves the accuracy of determining morphological changes at the initial stages of the dam-break flow. A good agreement between the model solutions and the experimental data is observed.

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On dam-break wave propagation and its implication to sediment erosion

Cited by 13 publications

References 36 publications

Experiments on initial stages of development of dam-break waves

Experiments on initial stages of development of dam-break waves

Stochastic Uncertainty in a Dam-Break Experiment with Varying Gate Speeds

Effects of initial stage of dam-break flows on sediment transport

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