Figure Investigation of Hydraulic Characteristics of Vertical Drops with Screens and Gradually Wall Expanding with FLOW3D Software

Behnam Nayebzadeh

Image Presentation

Investigation of Hydraulic Characteristics of Vertical Drops with Screens and Gradually Wall Expanding

Year 2025, Volume: 9 Issue: 2, 1 - 18

Abstract

In the present study, we investigated the hydraulic Characteristics of vertical Drops with Screens and the Gradually Wall Expanding in downstream using Flow-3D software. For this purpose, two porosity ratio of the screens of 40 and 50%, 5 gradually expanding with 3 vertical Drops heights in the specified discharge range were used. VOF fluid volume component method to simulate free surface flow and RNG and k-ε models for turbulence were used. The validation was performed by comparing the pool depth with the laboratory results. It was found that the numerical results are closer to the experimental results with the RNG turbulence model than k-ε. Also, by increasing the drop height from 15 to 25 cm, the energy dissipation due to the jet floor impact intensity increases and the pool depth decrease. The highest energy dissipation for 25 cm height was 51.60% and the lowest for 15 cm height was 44.25%. It was observed that for a constant drop height with increasing discharge, the energy dissipation decreased and the pool depth increased. The Gradually Wall Expanding causes turbulence on the edges and a Non-uniform distribution of the downstream depth and by increasing the pool and downstream depths it causes a 25% increase in energy dissipation. The presence of screens downstream of the drop increases of the pool depth, downstream depth, and also increases the energy dissipation by 44%. It was found that the simultaneous use of Gradually Wall Expanding and screens in downstream of the drops resulted in a 46% increase in energy dissipation and a decrease in pool and downstream depths. In the end, it was proved that the participatory share of screens is greater than the Gradually Wall Expanding, and the simultaneous use of the screens and the Gradually Wall Expanding can increase the participatory share of energy dissipation by up to 33.5%.

Keywords

Vertical Drop , Porosity ratio , Turbulence Models , Gradually Wall Expanding , Flow-3D.

Project Number

References

[1] Moore, W.L. (1943). Energy loss at the base of a free overfall. Transactions of the ASCE, 108(1), 1343–1360.
[2] Rajaratnam, N., Chamani, M.R. (1995). Energy Loss at Drops. Journal of Hydraulic Research, 33(3), 373–384.
[3] Esen, I.I., Alhumoud, J.M., Hannan, K.A. (2004). Energy Loss at a Drop Structure with a Step at the Base. Water International, 29(4), 523–529.
[4] Chamani, M.R., Rajaratnam, N., Beirami, M.K. (2008). Turbulent jet energy dissipation at vertical drops. Journal of Hydraulic Engineering, 134(10), 1532–1535.
[5] Hong, Y.M., Huang, H.S., Wan, S. (2010). Drop characteristics of free-falling nappe for aerated straight-drop spillway. Journal of Hydraulic Research, 48(1), 125–129.
[6] Katourany, S., Kashefipour, S.M. (2014). Effect of the Geometric Characteristics of Baffled and Bed Slopes of Drop on Hydraulic Flow Conditions in Baffled Apron Drop. Science and Irrigation Shahid Chamran Ahwaz, 37(2), 51–59. (in Persian)
[7] Mansouri, R., Ziaei, A.N. (2014). Numerical modeling of the flow in the vertical drop with inverse apron. Proc. 11th Int. Conf. on Hydroinformatics, NYC, USA.
[8] Sadeghfam, S., Akhtari, A.A., Daneshfaraz, R., Tayfur, G. (2015). Experimental investigation of screens as energy dissipaters in submerged hydraulic jump. Turkish J. of Engineering and Environmental Sciences, 38(2), 126–138.
[9] Daneshfaraz, R., Sadeghfam, S., Rezazadeh Joudi, A. (2017). Effect of screen location on flow energy dissipation. Irrigation and Drainage Structures Engineering Research, DOI:10.22092/aridse.2017.109616. 17(67), 47–62. (in Persian)
[10] Daneshfaraz, R., Sadeghfam, S., Ghahramanzadeh, A. (2017). Three-dimensional numerical investigation of flow through screens as energy dissipators. Canadian Journal of Civil Engineering, DOI: 10.1139/cjce-2017-0273 . 44(10), 850–859.
[11] Kabiri-Samani, A.R., Bakhshian, E., Chamani, M.R. (2017). Flow characteristics of grid drop-type dissipators. Flow Measurement and Instrumentation, 54, 298–306.
[12] Ghaderi, A., Dasineh, M., Abbasi, S. (2019). Impact of vertically constricted entrance on hydraulic characteristics of a vertical weir. Journal of Hydraulics, 13(4), 121–131.
[13] Daneshfaraz, R., Sadeghfam, S., Hasanniya, V. (2019). Energy dissipation of vertical drops with a horizontal screen under supercritical flow. Iranian Journal of Soil and Water Research. DOI:10.22059/ijswr.2019.269301.668053 (in Persian)
[14] Norouzi, R., Daneshfaraz, R., Bazyar, A. (2019). Energy dissipation using a vertical screen downstream of inclined drops by ANFIS. AUT Journal of Civil Engineering. DOI:10.22060/CEEJ.2019.16694.6305 (in Persian)
[15] Sadeghfam, S., Daneshfaraz, R., Khatibi, R., Minaei, O. (2019). Scour of supercritical jets upstream of screens and AI-based modeling. Journal of Hydroinformatics. DOI : 10.2166/hydro.2019.076. 21 (5): 893–907
[16] Hager, W.H. (1985). Hydraulic jump in non-prismatic rectangular channels. Journal of Hydraulic Research, 23(1), 21–35.
[17] Grant, D.M., Dawson, B.D. (1998). Open Channel Flow Measurement Handbook. 5th ed., ISCO Inc.
[18] Çakir, P. (2003). Experimental investigation of energy dissipation through screens. MSc thesis, METU, Ankara.
[19] Balkiş, G. (2004). Experimental Investigation of Energy Dissipation through Inclined Screens. PhD thesis, METU, Ankara.
[20] Flow Science, Inc. (2008). FLOW-3D User's Manual (v9.3). Santa Fe, NM.
[21] Daneshfaraz, R., Ghahramanzadeh, A., Ghaderi, A., Joudi, A.R., Abraham, J. (2016). Effect of edge shape on flow under vertical gates. Journal–AWWA, 108(8), 425–432.
[22] Daneshfaraz, R., Minaei, O., Abraham, J., Dadashi, S., Ghaderi, A. (2019). 3-D simulation of flow over a broad-crested weir with openings. ISH Journal of Hydraulic Engineering. DOI: 10.1080/09715010.2019.1581098. 27(1), 88-96.
[23] Versteeg, H.K., Malalasekera, W. (2007). An Introduction to CFD: The Finite Volume Method. Pearson Education.
[24] Nayebzadeh, B., Lotfolahi-Yaghin, M.A., Daneshfaraz, R. (2019). Experimental study of energy dissipation at a vertical drop with vertical screen and gradual downstream expansion. AUT Journal of Civil Engineering. DOI:10.22060/CEEJ.2019.16493.6265. 52 (12), 3059-3072
[25] Süme, V., Daneshfaraz, R., Kerim, A., Abbaszadeh, H., Abraham, J. (2024). Investigation of Clean Energy Production in Drinking Water Networks. Water Resour Manage. DOI: 10.1007/s11269-024-03752-9. 38, 2189–2208
[26] Hassanzadeh,Y., Abbaszadeh, H., Abedi, A., Abraham, J. (2024). Numerical simulation of the effect of downstream material on scouring-sediment profile of combined spillway-gate. AQUA - Water Infrastructure, Ecosystems and Society. DOI:10.2166/aqua.2024.360. 73 (12): 2322–2343.
[27] Abbaszadeh, H., Daneshfaraz, R., Sume, V., Abraham, J., (2024). Experimental investigation and application of soft computing models for predicting flow energy loss in arc-shaped constrictions. AQUA - Water Infrastructure, Ecosystems and Society. doi: https://doi.org/10.2166/aqua.2024.010. 73 (3): 637–661.
[28] Daneshfaraz R., Norouzı R., Akhondı B., Süme V., Marangoz H. O., Yılmaz E., (2025), Experimental investigation of the effect of perforated sill and orifice on sluice gate discharge coefficient, Water Science. DOI: 10.1080/23570008.2025.2574772. 39 (1), 426-434.
[29] Aminash, E., Daneshfaraz,R., Sume,V., Sadeghfam, S., Abraham, J.A.,(2025), On the Multiple Steady Flow States in Spindle Shaped Geometry of Bridge Foundations Journal of Applied Fluid Mechanics. DOI: 10.47176/jafm.18.1.2668. 18 (1), 1-15.