Numerical Assessment of the Performance of Bed Water Jets in Submerged Hydraulic Jumps

Helal, Esam; Abdelhaleem, Fahmy Salah; Elshenawy, Wafaa A.

doi:10.1061/(asce)ir.1943-4774.0001475

Cited by 14 publications

(7 citation statements)

References 28 publications

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“…According to Figure 5 , the overall trend of the simulated mean free-surface profile and bottom velocity profile agreed well with the experimental results. To quantify the reliability of the numerical simulation, the root mean square error (RMSE) and the mean absolute percent error (MAPE) were used to evaluate the accuracy of the numerical results [ 26 ]. For the mean free-surface profile, the associated RMSE and MAPE were 0.048 m and 13.2%, respectively.…”

Section: Resultsmentioning

confidence: 99%

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Investigation of a Negative Step Effect on Stilling Basin by Using CFD

Jiang

Diao

Wang

2022

Entropy

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The negative-step stilling basin is an efficient and safe energy dissipator for high-head, large-unit discharge high-dam projects. However, studies of the effects of the negative step on the hydraulic performance of a high-dam stilling basin have not been conclusive. In the present study, a 2D RANS-VOF numerical model was developed to simulate the flow field of a negative-step stilling basin. The numerical model was validated with a physical model and then used to simulate and test the performance of the negative-step stilling basin with different step heights and incident angles. The results showed that the flow pattern, the free-surface profile, the velocity profile, the characteristic lengths are strongly influenced by the step geometry. Increasing the height of the step will increase the relative flow depth and the reattachment length in the basin, but reduce the bottom velocity and the roller length. The incident angle has no significant influence on the flow pattern of the negative-step stilling basin, and increasing the incident angle of the step will reduce the bottom velocity and the reattachment length. Both the step height and the incident angle have no significant influence on the energy dissipation efficiency because of the high submergence conditions in this study.

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Section: Resultsmentioning

confidence: 99%

“…Based on the VOF method, α = 1 denotes a region that is fully inundated with water, and α = 0 corresponds to air. The free-surface volume fraction was specified to be α = 0.5 [ 26 ]. The governing equations were numerically solved using Fluent computer code (ANSYS FLUENT Academic v.19.0).…”

Section: Numerical Simulationsmentioning

confidence: 99%

Investigation of a Negative Step Effect on Stilling Basin by Using CFD

Jiang

Diao

Wang

2022

Entropy

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“…They indicated optimal behavior when the jet is inclined at 45 • and when it is located in the jump area, approaching the upstream section. Varol et al [15] investigated the effect of water jets on the characteristics of hydraulic jumps, in terms of flow structure, roller length, water surface profiles, and energy losses, while Helal et al [16] confirmed the performance of this kind of dissipation device in improving the efficiency of submerged hydraulic jumps.…”

Section: Introductionmentioning

confidence: 99%

Experimental Analysis on the Use of Counterflow Jets as a System for the Stabilization of the Spatial Hydraulic Jump

Sharoonizadeh

Ahadiyan

Scorzini

et al. 2021

Water

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This study presents an investigation on the use of submerged counterflow jets as a means for stabilizing the spatial hydraulic jump occurring in abruptly expanding channels. The characteristics of the flow downstream from the stilling basin and the main parameters influencing the effectiveness of the device in improving flow uniformity and reducing scouring potential are examined in laboratory tests, under several geometric configurations and hydraulic boundary conditions. The position within the stilling basin and the jet density (i.e., the number of orifices issuing the counterflow jets) were found to be important parameters influencing the performance of the device. Overall, the results indicate that this dissipation system has promising capabilities in forcing the transition from supercritical to subcritical flow, by significantly shortening the protection length needed to limit the phenomena of instability associated with spatial hydraulic jumps.

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“…High-pressure water jet washing is the key technology of automobile washer [4,5]. It has been widely used because of its strong decontamination capability, wide application range, no environmental pollution, and easy automation [6][7][8][9][10]. It provides the basis for the automatic control of the car washing industry [11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Research on the Influence of External Parameters of Fan-Type Nozzle on Water Jet Performance

Kou

Huo

Hou

2020

Shock and Vibration

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At present, high-pressure water jet technology occupies a very important position in the automobile washing industry. Some automatic washers cannot meet the washing requirements in the washing process due to unreasonable arrangement of nozzles on their spray rods. Based on the theory of computational fluid dynamics (CFD), the internal and external flow field model of the nozzle are established in this paper. Fluent is used to simulate and analyze the flow field, and the external parameters of the nozzle on the side spray bar of the automatic automobile washer are optimized. The simulation results show that after the nozzle and the normal line of the automobile surface are inclined at a certain angle, the target surface is affected not only by normal striking force but also by tangential pushing force, which makes stains easier to remove. The washing effect is the best when the nozzle is inclined 30° to the normal line of the automobile surface. Increasing the nozzle inlet pressure will increase the dynamic pressure on the automobile surface, but the increase of dynamic pressure will decrease after increasing to a certain pressure. The inlet pressure has little effect on the area covered by water jet. The reasonable matching results of jet angle, nozzle spacing, and nozzle distance from the automobile surface (target distance) obtained by numerical simulation can not only make the automobile surface completely covered and cleaned but also ensure less jet interference and no waste of water from adjacent nozzles. The above research conclusions can provide a basic theoretical basis for the optimal design of automatic automobile washing.

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Numerical Assessment of the Performance of Bed Water Jets in Submerged Hydraulic Jumps

Cited by 14 publications

References 28 publications

Investigation of a Negative Step Effect on Stilling Basin by Using CFD

Investigation of a Negative Step Effect on Stilling Basin by Using CFD

Experimental Analysis on the Use of Counterflow Jets as a System for the Stabilization of the Spatial Hydraulic Jump

Research on the Influence of External Parameters of Fan-Type Nozzle on Water Jet Performance

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