Experimental and Numerical Investigation of the Trajectory of Outlet Jets through the Pressurized Discharge Gates of Reservoir Dams

آب و توسعه پایدار

Article 10, Volume 10, Issue 3 - Serial Number 29, December 2023, Pages 109-120   

Document Type: Applied Article

DOI: 10.22067/jwsd.v10i3.2301-1207

Authors

A. Taheri Aghdam^{* 1}; F. Salmasi²; A. Hosseinzade Dalir²; A. Abbaspour³

¹Ph.D. Student, Department of Water Engineering, Tabriz University, Tabriz, Iran

²Professor, Department of Water Engineering, Tabriz University, Tabriz, Iran

³Associate Professor, Department of Water Engineering, Tabriz University, Tabriz, Iran

Abstract

Accurate knowledge of where jets hit downstream of dams helps designers a lot in locating plunging pools. The purpose of this study is to investigate experimentally and numerically the trajectory of pressurized jets through the gates and to determine their location downstream of the dam. Ansys - Fluent software was used for numerical simulation. The results showed that there is a significant difference between the experimental values and the values extracted from the jet projectile equations for predicting the path of the pressurized jets, and this discrepancy may be due to the effect of air resistance on flow. The existing jet trajectory equations don’t consider air resistance. To minimize this difference, the projectile equation was modified. Also, the effect of changing the diameter of the dam gate and the discharge on the point of impact of the pressurized jet on the ground surface was examined. By increasing the diameter of the dam outlet at a constant discharge, the location of impact of the impinging jet to the ground from the dam toe decreases, and with increasing discharge at a constant diameter of outlet, the place of impact of the pressurized jet to the ground from the toe of the dam increases. In addition, the numerical simulation results showed that the dynamic pressure as well as the velocity at the point of impingement of the jets on the river bed have the maximum value that should be considered in designs. The dynamic pressure as well as the velocity of the jet coming out of the gate hit the ground with an average increase of 145% and 242% relative to the end edge of the gate, respectively. In addition, the breaking length of the pressurized jet was investigated in this study, and it was found that the breaking length of the pressurized jet increases with the increase in the initial velocity of the water jet.

Keywords

Pressurized Jet; Plunging Pool; Gate; Dynamic Pressure; Projectile Equation

References

بهره بر، امیررضا، حیدرنژاد، محمد، مسجدی، علی رضا، و بردبار، امین. (1400). مطالعه عددی و آزمایشگاهی ترکیب سرریز کنگره‌ای با روزنه و تأثیر آن بر ضریب دبی جریان. مجله علوم آب و خاک، ۲۵(۲)، 91-۱۰۵. DOI: 10.47176/jwss.25.2.38095
سلمان‌زاده، سمیرا، و احدیان، جواد. (1395). پراکنش حدی جریان جت خروجی در محیط هم فاز و غیر هم‌فاز، فصلنامه علوم و مهندسی آبیاری، 39(1)، 93-107. DOI: 10.22055/JISE.2016.12015
سلماسی، فرزین، نورانی، بهرام، نوروزی، رضا، و رضایی، فائزه. (1400). بررسی رابطه دبی- اشل و ضریب دبی جریان در سرریزهای لبه تیز پلان مثلثی. نشریه مهندسی عمران امیرکبیر، 53(5)، 1689-1704. DOI: 10.22060/ceej.2019.16931.6399
غفاری، سعید، اقبال‌زاده، افشین، و جوان، میترا. (1395). بررسی عددی اثرات ارتفاع تاج روزنه‌ی جانبی مستطیلی لبه تیز بر الگو و مشخصات جریان در اطراف روزنه جانبی. مهندسی عمران مدرس; ۱۶(۲۰)، ۱2۹-۱3۹. URL: http://mcej.modares.ac.ir/article-16-1034-fa.html 
مرکز تحقیقات آب. (1381). مدل هیدرولیکی تخلیه کننده تحتانی سد البرز. گزارش نهایی. وزارت نیرو. تهران، ایران.
مرکز تحقیقات آب. (1382). مدل هیدرولیکی تخلیه کننده تحتانی سد گاوشان. گزارش نهایی. وزارت نیرو. تهران، ایران.
Ahadiyan, J., & Musavi Jahromi, S.H. (2009).  Effects of jet hydraulic properties on geometry of trajectory in circular buoyant jets in the static ambient flow. Journal of Applied Sciences, 9(21), 3843-3849. DOI: 10.3923/jas.2009.3843.3849
Ansys Fluent. (2015). Ansys Fluent Tutorial Guide, South pointe, 275 Technology Drive, Canonsburg, PA 15317, USA. 
Akbari, M., Salmasi, F., Arvanaghi, H., Karbasi, M., & Farsadizadeh, D. (2019). Application of Gaussian Process Regression Model to Predict Discharge Coefficient of Gated Piano Key Weir. Water Resources Management,  33(11), 3929–3947. https://doi.org/10.1007/s11269-019-02343-3
Ervine, D.A., & Falavey, H.T. (1987). Behavior of Turbulent Jets in Atmosphere and in Plunge Pools. Proceeding of The Institution of the Civil Engineering, Part 2,  83(1), 295-314. DOI: 10.1680/iicep.1987.353
Eggers, J. (1997). Nonlinear Dynamics and Breakup of Free Surface Flows. Reviews of Modern Physics, 69(3), 865-929.  DOI: 10.1103/REVMODPHYS.69.865
Hirt, W., & Nichols, B.D. (1981). Volume of fluid (VOF) method for the dynamics of free boundaries, Journal of Computational Physics, 39, 201–225. https://doi.org/10.1016/0021-9991(81)90145-5
Kamoi, A., & Tanaka, H. (1972). Measurements of wall share stress, wall pressure and fluctuations in the stagnation region produced by oblique jet impingement, Fluid dynamic measurements conference. University of Leicester, United Kingdom.
Malekzadeh, F., Salmasi, F., Abraham, J., & Arvanaghi, H. (2022). Numerical investigation of the effect of geometric parameters on discharge coefficients for broad-crested weirs with sloped upstream and downstream faces. Applied Water Science, 12, 1-15, https://doi.org/10.1007/s13201-022-01631-5
Nourani, B., Arvanaghi, H., & Salmasi, F. (2021).  Effects of different configurations of sloping crests and upstream and downstream ramps on the discharge coefficient for broad-crested weirs. Journal of Hydrology, 603(B), 126940. https://doi.org/10.1016/j.jhydrol.2021.126940
Salmasi, F., & Abraham, J. 2022. Multivariate Nonlinear Regression for Predicting Free Falling Jet Scouring: An Experimental Study. Iranian Journal of Science and Technology. Transactions of Civil Engineering, 46, 3859–3870. https://doi.org/10.1007/s40996-022-00817-w
Salazar, F., San-Mauro, J., Celigueta, M., & Onate, E. (2016). Air demand estimation in bottom outlets with the particle finite element method. Journal of Computational Particle Mechanics, 4(3), 345-356. DOI: 10.1007/s40571-016-0117-4
USBR, US Bureau of Reclamation. (1960). Design of small dams. United States Department of the Interior. United States Government Printing Officeو Denver, USA. pp: 282–291.
USBR, US Bureau of Reclamation. (1976). Design of gravity dams. United States Department of the Interior. United States Government Printing Office. Denver, USA. pp: 198–199.
USBR, US Bureau of Reclamation. (1977). Design of arch dams. United States Department of the Interior. United States Government Printing Office. Denver, USA. pp: 312–313.
USACE, U.S. Army Corps of Engineers. (1980). Hydraulic design criteria. Coastal and Hydraulics Laboratory. Engineer Research and Development Center. Waterways Experiment Station. Vicksburg, USA. pp: 8-12.
Zhang, W., & Zhu, D. (2014). Trajectories of air-water bubbly jets in cross flows. Journal of Hydraulic Engineering. American Society of Civil Engineers 140(7), 06014011. https://doi.org/10.1061/(ASCE)HY.1943-7900.000088