بررسی عددی میدان جریان روی سرریز اوجی تحت تاثیر شکل تاج و شیب وجه بالادست سرریز

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد مهندسی آب و سازه‌های هیدرولیکی، دانشگاه آیت اله العظمی بروجردی(ره)

2 دانشیار گروه عمران، دانشگاه آیت‌اله‌العظمی بروجردی (ره).

چکیده

در این پژوهش، الگوی جریان سرریز اوجی تحت تاثیر شکل منحنی تاج سرریز و تغییرات شیب وجه بالادست سرریز، با استفاده از نرم‌افزار شبیه­ساز عددی  Flow-3Dمورد ارزیابی قرار گرفت. بدین ترتیب دو سرریز اوجی با تاج بیضوی و الگوی USBR در دو حالت وجه بالادست قائم و مایل با شیب 3H:3V و به­ازای سه هد مختلف، شبیه­سازی شدند و نتایج حاصل از تغییرات پارامترهای موثر نظیر دبی، سرعت و فشار در طول هر یک از سرریز­ها مورد بررسی قرار گرفت. صحت‌سنجی نتایج مدل عددی با نتایج مدل آزمایشگاهی ماینورد نشان داد مدل عددی Flow-3D از توانایی بالایی برای شبیه‌سازی میدان جریان روی سرریز اوجی برخوردار است. مقایسه دبی حاصل از مدل عددی با داده­های آزمایشگاهی، بیان‌گر میانگین خطای محاسباتی زیر سه درصد مدل عددی بود. بررسی میدان فشار نشان داد در ارتفاع هد برابر هد طراحی، فشارها نزدیک فشار اتمسفر می­باشند و فشار منفی روی تاج سرریز ایجاد نشده است اما در هد بالاتر از هد طراحی روی سرریز فشار منفی به‌وجود خواهد آمد. مقدار فشار منفی ایجاد شده در ابتدای تاج سرریز USBR نسبت به مقدار فشار منفی تاج سرریز بیضی شکل، بیش‌تر است و دلیل آن عدم پیوستگی در تاج و جدایی بیش‌تر خطوط جریان از روی آن است. همچنین نتایج نشان داد که سرریز اوجی با تاج بیضی شکل، عملکرد نسبتا بهتری در جریان عبوری از روی سرریز دارد و در این سرریزها امکان عبور دبی­ بیش‌تر با ایمنی بالاتری فراهم می­شود و شیب­دار کردن وجه بالادست سرریز باعث تغییر در ضریب تخلیه و نهایتاً میزان دبی عبوری جریان از روی سرریز می‌شود. 

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Numerical Investigation of the Flow Field on the Ogee Spillway under the Influence of the Crest Shape and Slope of the Upstream Face of the Spillway

نویسندگان [English]

  • Mehdi Lak 1
  • Mehdi Komasi 2
1 Department of Civil Engineering, Ayatollah Boroujerdi University.
2 Associate Professor, Department of Civil Engineering, Ayatollah Boroujerdi University
چکیده [English]

In this study, the ogee spillway flow pattern under the influence of the spillway curve shape and upstream slope changes was evaluated using Flow-3D numerical simulator software. Thus, two ogee spillways with elliptical crest and USBR pattern were simulated in two vertical and oblique upstream modes with a slope of 3H:3V and three different heads, and the results of changes in effective parameters such as flow, velocity and pressure in the length of each spillway was examined. Validation of the results of the numerical model with the results of the Maynord experimental model showed that the Flow-3D numerical model has a high ability to simulate the flow field on the ogee spillway. Comparison of flow rate from numerical model with experimental data showed that the average computational error was less than 3% of the numerical model. Examination of the pressure field showed that at the height of the head equal to the design head, the pressures are close to atmospheric pressure and no negative pressure is created on the spillway crest, but at the head higher than the design head, negative pressure will be created on the spillway. The amount of negative pressure created at the beginning of the USBR spillway crest is higher than the negative pressure value of the elliptical spillway crest due to the lack of continuity in the crest and further separation of the flow lines from it.  The results also showed that the ogee spillway with oval crest has a relatively better performance in the flow over the spillway and in these spillways it is possible to pass more discharge with higher safety and sloping the upstream side of the spillway causes a change in the discharge coefficient and finally the flow rate of the spillways.

کلیدواژه‌ها [English]

  • Ogee Spillway
  • Numerical simulation
  • Flow3d
  • Finite Volume
  • Pressure distribution

مراجع

[1] U.S. Bureau of Reclamation, (1977). “Design of small dams”. U.S. Government Priming Office, Washinton, D.C, 904, 383-415.
[2] Mousavimehr, S. M., Aminoroayaie Yamini, O., & Kavianpour, M.R. (2021). “Performance Assessment of Shock waves of Chute Spillways in Large Dams”, Journal of Shock and Vibration, vol.  Article ID 6634086, 1-17.
[3] Bruce, M., Savage, M., Johson, Members, C., & ASCE, (2001). “Flow over ogee spillway: physical and numerical model case study”, J. Hydr.Eng (ASCE), 127(8), 640-649.
[4] Barzegari, M., Sobhkhiz Foumani, R., Isari, M., Tarinejad, R., & Alavi, S.A. (2019) “Numerical Investigtion of Cavitation on Spillways. A Case Study: Aydoghmush dam”, NMCE, 4(1), 1-9. 
[5] Parsaie, A., Dehdar-Behbahani, S., & Haghiabi, A.H. (2016). “Numerical modeling of cavitation on spillway’s flip bucket”, Journal of Front. Struct. Civ. Eng., 10, 438–444.
[6] Dargahi, B. (2006). “Experimental Study and 3D Numerical Simulations for a Free-Overflow Spillway”. Journal of Hydraulic Engineering, ASCE, 132(9).
[7] Bhajantri, M.R., Eldho T.I., & Deolalikar, P.B. (2006). “Hydrodynamic modeling of flow over a spillway
using a two-dimensional finite volume-based numerical model”, Journal of Sadhana, 20(1), 743-754.
[8] Cassidy, J. (1970). “Designing spillway crests for high-head operation”, Journal of Hydr. Eng. (ASCE), 96(3), 745-753.
[9] Maynord, S.T. (1977). “Hydraulic Design Criteria”, Revision 17, U.S. Army Corps of Engineers, Vicksburg.
[10] Maynord, S.T. (1948). “Studies of Crests of Overfall Dams”, Boulder Canyon final reports, Bureau of Reclamation, U.S. Department of the Interior, Washington DC.
[11] Cassidy JJ (1965). “Irrotational flow over spillways of finite height”, Journal of Eng. Mech. Div. ASCE., 91(6), 155-173.
[12] Olsen, N.R.B., & Kjellesvig, H.M. (1998). “Three Dimensional Numerical Flow Modeling for Estimation of Spillway Capacity”, Journal of Hydr.Res, 36(5), 775-784.
[13] Burgisser, M.F., & Rutschmann, P., (1999). “Numerical Solution of Viscous 2D Vertical Free Surface Flows: Flow Over Spillway Crests”, Proc, 28th Iahr Congr., Technical University Graz, Graz, Austria.
[14] Tufi, M.A. (2001). “Solution for Spillway Flow by Finite Difference Method”, Journal of Hydraulic Researcs, 39(3), 241-247.
[15] Savage, B.M., and Johnson, M.C. (2001). “Flow Over Ogee Spillway: Physical and Numerical Model Case Study”, Journal of Hydraulic Engineering Asce, 127(8), 640-649.
[16] Shishegaran, A., Mohammadkhani, M.R., & Tavakoli, M.A. (2020). “Determination of Discharge Flow in Unit Width for the Distinction of Nappe and Skimming Flow in Stepped Spillway Using Flow 3d (Case Study: Siah Bishe Dam)”, Civil and Environmental Researches, Civil Infrastructure Researches, 5(2), 165-177.
[17] Aydin, M.C., & Ozturk, M. (2009). “Verification and validation of a computational fluid dynamics (CFD) model for air entrainment at spillway aerators” Can. J. Civ. Eng., 36, 826-836.
[18] Morales, V., Tokyay, T.E., & Garcia, M. (2012). “Numerical Modeling of Ogee Crest Spillway and Tainter Gate Structure of a Diversion Dam on Canar River”, Ecuador, XIX International Conference on Water Resources.
[19] Murphy, T.E. (1973). “Spillway crest design”, Misc. Paper H-73-5, U.S. Army Corps of Engineers Waterways Experiment Station, Vicksburg.
[20] Reese, A.J., & Maynord, S.T. (1987) “Design of spillway crests”, Journal of Hydraulic Engineering, 15, 476-490.
[21] Rouse, H., & Reid, L. (1935). “Model research on spillway crests”, J. Civ. Eng., 5(1), 11-16.
[22] Melsheimer, E.S., &, Murphy T.E., (1970). “Investigations of Various Shapes of the Upstream Quadrant of the Crest of a High Spillway”, Research report H-70-1, U.S. Army Engineer Waterways Experiment Station, Vicksburg.
[23] Karimi Pirmoosaei, F., Mardookhpour, A.R., & Tavakoli, M.A. (2020) “Numerical Simulation of Cavitation Phenomenon in the Stepped Spillway with Fluent Software”, Civil Infrastructure Researches, 6(1), 127-1.
[24] Maynord, S.T. (1985). “General Spillway Investigation”, Technical report HL 85-1, U.S. Army Corps of Engineers Waterways Experiment Station, Vicksburg.
[25] Farzin, S., Karami, H., Yahyavi, F., & Nayyer, S. (2018). “Numerical study of hydraulic characteristics around the vertical and diagonal sharp crested weirs using Flow3D simulation”, Civil and Environmental Researches, Civil Infrastructure Researches, 4(1), 15-24. 
[26] Andrew, j., Reese, M. ASCE., Stephen, T., and Maynord, A.M. ASCE. (1987). “Design of Spillway Crests”. Journal of Hydraulic Engineering, (ASCE), 15, 476-490.
[27] Flow Science Inc. (2002). FLOW-3D user’s manual. 
[28] Versteeg, H. K., & Malalasekera, W. (2007). “An Introduction to Computational Fluid Dynamics”.
[29] Heydari, M. (2003). “Flow simulation on ogee spillway using fluent package”, MSc Thesis, Faculty of Engineering, Iran.
[30] Emami, S., & Parsa, J. (2019) “Numerical Investigating of Flow and Discharge Coefficient Over the Duckbill and Oblique Weirs”, Civil and Environmental Researches, 5(1), 135-145.
[31] Hirt, C. W., & Nichols, B. D. (1981). “Volume of fluid (VOF) method for the dynamics of free boundaries”, Journal of Computational Physics, 39, 201-225.
[32] Szymkiewicz, R. (2010). “Numerical modeling in open channel hydraulics”, 83 Springer Science & Business Media, https://doi.org/10.1007/978-90-481-3674-2.
[33] Gourbesville, P., Cunge, J. A., & Caignaert, G. (2015). “Advances in Hydroinformatics”: SIMHYDRO 2014. Springer.
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