Characteristics of hydraulic jump on rough bed with adverse slope

Parsamehr, P; Farsadizadeh, D; Dalir, A Hosseinzadeh; Abbaspour, Akram; Esfahani, Mohammad Javad

doi:10.1080/09715010.2017.1313143

Cited by 29 publications

(6 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In an experimental study, the characteristics of the hydraulic jump on a roughened bed with an adverse slope were evaluated. The results revealed that increasing height of the roughness, as well as the adverse slope leads to drop of jump length and sequent flow depth [16,17]. A study of Alhamid [8] showed that the S-jump has the higher efficiency and smaller conjugate depth ratio, in comparison to the classical jump.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Investigating the Pressure Fluctuations of Hydraulic Jump in an Abrupt Expanding Stilling Basin with Roughened Bed

Hasani

Nekoufar

Biklarian

et al. 2022

Water

View full text Add to dashboard Cite

Stilling basins with sudden expansions are one of the energy dissipation structures. In the hydraulic jump, pressure fluctuations cause significant damages in stilling basins by cavity formation, erosion, and vibration. Roughness can also lead to changes of the behavior of stream lines and vortices. Despite the large number of works on the topic, the role of roughness in spatial hydraulic jumps is not yet fully understood. Present research aimed to study the influence of rough bed on pressure fluctuations of S-jump in abrupt expanding stilling basin. Experiments were conducted in a 0.8 m width and 12 m length flume. Channel expansions ratios were 0.33, 0.5, 0.67, and 1 within the range of Froude numbers, 2 to 9.5. The results showed that roughness decreases intensity of pressure fluctuations in an abrupt expansion stilling basin. Additionally, in sudden expanding sections, the energy loss increases, and the intensity of pressure fluctuations decrease due to the formation of lateral vortices. The reduction rate of maximum pressure fluctuation was 27%, 46%, and 58% for expansion ratio of 0.67, 0.5, and 0.33, respectively. The results revealed the clear dependence of these variables on the Froude number and the distance to the hydraulic jump toe. The maximum values of extreme pressure fluctuations occur in the range 0.609 < X < 3.385, where X is dimensionless distance from the toe of the hydraulic jump, which makes it highly advisable to reinforce the bed of stilling basins in this range.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Investigating the Pressure Fluctuations of Hydraulic Jump in an Abrupt Expanding Stilling Basin with Roughened Bed

Hasani

Nekoufar

Biklarian

et al. 2022

Water

View full text Add to dashboard Cite

show abstract

“…From the results, it was inferred that the flow is retarded in the inner layer of the wall jet due to the presence of the bed and is accelerated in the outer region of the wall jet due to the circulatory flow in the roller region. Parsamehr et al [16] experimentally investigated the characteristics of hydraulic jump on rough bed with discontinuous roughness elements of lozenge shape over adverse slope. They found that by increasing the height of roughness elements and steeping the adverse slope, the sequent depth ratio, and relative length of the jump decreased while the energy loss increased.…”

Section: Figure 1 A) Rooster Tail Jump In Horseshoe Spillway B) Horsmentioning

confidence: 99%

Experimental Study of the Rooster Tail Jump and End Sill in Horseshoe Spillways

2019

View full text Add to dashboard Cite

In a horseshoe spillways, due to the collision of the falling nappes from their surround walls, in the center of spillway’s trough, a spatial hydraulic jump is formed that named “rooster tail”. This study by using the physical model of horseshoe spillway, investigates the form, height and length of rooster tail jump. Based on the analytical methods, the effective parameters on rooster tail jump’s height and height were determined and their interaction was investigated and linear relationships were proposed to predict jump’s length and height. By increasing the amount of water on the spillway’s crest and thereby increasing the velocity of flow nappe at the point of contact with the spillway’s bed, length and high of rooster tail jump, linearly increased. The result also shows that by increasing number of Froude, the length and height of jump increases and by increasing the spillway’s length, the height and length of the rooster tail jump decreases. To control of rooster tail jump in spillway’s model, two different size of end sills Inserted at downstream of spillway and result shows that by employing a sill with height of 3.8 cm and 7.6 cm, the flow depth, in average, respectively 122% and 272% increase compared to no sill conditions, also flow state change from super-critical to sub-critical. At the sill of 3.8 cm it was observed that the rooster tail jump did not submerged, but at the height of 7.6 cm the jump submerged and static pressure increased more. The results revealed that by placing the sill of 3.8 and 7.6 cm, respectively 45% and 35% of the maximum pressure entering the bed of the spillway at the collision site is reduced.

show abstract

“…They found that the sill with two steps has better efficiency to stabilize a jump in the stilling basin compared to sill with three steps. Parsamehr et al (2017) have investigated the characteristics of hydraulic jump, including sequent depth, relative length of the jump, and energy loss on rough bed with discontinuous roughness elements of lozenge shape over adverse slope. It was found that by increasing the height of roughness elements and steeping the adverse slope, the sequent depth ratio, and relative length of the jump decreased, while the energy loss increased.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of the hydraulic jump on reverse bed with porous screens

2019

View full text Add to dashboard Cite

Nowadays, the porous screens have been used extensively in open channels to prevent erosion in ditches as the water in supercritical state flows past the screen which forces the formation of a hydraulic jump upstream of the screen and produces significant energy loss. In this investigation, the operation of screens has been studied for supercritical flow and the Froude number in the range of 4.5 to 10.6 on two reverse slopes experimentally. In this study, the parameters included arrangements of screens in both the single and double types, and the angle and distance of screens from the hydraulic jump toe. The screens were studied with a porosity of about 50% with square holes. The study results showed that using of screens on the reverse slope of − 0.025 dissipates more energy compared to reverse slope of − 0.015. The screens with double arrangement have better performance and dissipate more energy than the screens with single arrangement, while the distance of screens from the toe of the hydraulic jump does not have a significant effect on the energy dissipation.

show abstract

Characteristics of hydraulic jump on rough bed with adverse slope

Cited by 29 publications

References 13 publications

Investigating the Pressure Fluctuations of Hydraulic Jump in an Abrupt Expanding Stilling Basin with Roughened Bed

Investigating the Pressure Fluctuations of Hydraulic Jump in an Abrupt Expanding Stilling Basin with Roughened Bed

Experimental Study of the Rooster Tail Jump and End Sill in Horseshoe Spillways

Experimental study of the hydraulic jump on reverse bed with porous screens

Contact Info

Product

Resources

About