The Numerical Investigation of hydraulic condition on flip bucket spillways and effect of inlet flow and shape on it

Document Type : Research Article


1 Department of Civil Engineering, Parand & RobatKarim Branch, Islamic Azad University

2 Civil Aviation Technology


Since beginning of the dam construction industry, one of the challenges that engineers have always been involved with, is how to reduce the enormous energy of water when it overflows from dams for which, many plans and ideas have been presented so far. One of these ideas is to utilize the energy dissipater structures among which, the flip buckets are well-known. Since the flip bucket is one of the most important components of a dam, whose destruction disrupts the normal performance of the dam, the engineers have always tried to enhance the efficiency of this component by investigating into the hydraulic conditions such as pressure, depth and velocity. Accordingly, it is of paramount significance to comprehensively study the hydraulic performance and condition of the flip buckets
In this study, behavior of the fluid in the flip bucket of a dam has been modeled using Flow-3D software. The obtained results in Froude number, were compared with the data derived from an existing physical model. After determining the error percentage and selecting the turbulence model etc., using the continuity and motion equations in the fluid dynamics and finite volume method, a model was built and through a trial-and-error process, Froude numbers ranging from, 2 to 7 were chosen. The results pertained to the velocity, static pressure and depth were captured and compared with geometric characteristics of the bucket and incoming flow condition. To efficiently employ the results, the produced graphs were normalized using a similitude analysis. The comparisons have been made with the non-dimensional ratios of Froude number and x/r (x: distance from the bucket and r: bucket radius) in the middle as well as right and left sides
Results and Discussion
In order to choose the turbulence model (K-ε, K-ω and RNG turbulence models were used to compare the results of various models according to previous studies), after analyzing and optimizing the computational error between the numerical and the physical models, the k-ε model with the minimum rate of error was selected as the best practice. It needs to be noted that the error rate of pressure, velocity and depth are 1.52%, 1.5% and 1.58%, respectively. The results indicated that the velocity changes along the length of the bucket, generally have a slight increasing trend and reach their maximum value at the end of the bucket. In addition, velocity changes have an inverse trend as the Froude number increase. Moreover, it was observed that the depth changes are almost constant along length of the bucket and reach their minimum value at the end and decrease with the depth as the Froude number increases. Pressure changes also have a decreasing trend along the length of the bucket and also, decrease with increase in the Froude number. The situation of the above parameters in the sides is generally similar to the middle axis, but with a greater intensity
It can be generally stated that the most vulnerable zone of the flip bucket is where 0.1<x/r<0.3 (i.e., the region where flow runs backs to the top) in great Froude numbers. This zone is the critical area of the bucket structure due to the decrease in pressure, both in terms of the possibility of cavitations and increasing velocities. Furthermore, it was found that rate of vulnerability in the sides is greater than the middle. Moreover, range of the pre-final Froude numbers of the flow passing through to the bucket, is the turning point of the flow hydraulic condition that needs to be considered while designing this structure.


Main Subjects

Amin-o-roayaie Yamini, O., Kavianpour, M.R., Mousavi, H.S., Movahedi, A. & Bavandpour, M. (2018). Experimental investigation of pressure fluctuation on the bed of compound flip buckets. ISH Journal of Hydraulic Engineering, 24(1), 45-52. DOI: 10.1080/09715010.2017.1344572
Deng, J., Wangru, W., Tian, Z., Zhang, F. & Yang, Z. (2020). Analysis of Pressure Differences and Water Transverse Movement in a Partial-Flip Bucket. Journal of Hydraulic Engineering, 146(9), 04020063. 1943- 7900.0001780.
Ebrahimnejadian, H., Manafpour, M. & Babazadeh, V. (2020). Simulation of the Effect of Flip Bucket Edge Angle on Flow Hydraulic Characteristics. Iranian Journal of Soil and Water Research, 51(8), 2085-2100. (in Persian)
Kakeshpour, M., Pirestani, M.R. & Zakeri Niri, M. (2017). The effect of the shape in flip bucket thrower shot by using a numerical model. Journal of Water and Soil Conservation, 23(5), 223-237. (in Persian)
Khalifehei, K., Sadeghi Askari, M. & Azamathulla, H. (2022). Experimental investigation of energy dissipation on flip buckets with triangular deflectors. ISH Journal of Hydraulic Engineering, 28(1), 292-298, DOI: 10.1080/09715010.2020. 1775716.
Khorami, E., Heidari, M.M. & Ghobadian, R. (2020). Evaluation of the accuracy of the methods of determining the jet trajectory characteristics in Flip bucket. Environment and Water Engineering, 9(4), 499-514. (in Persian)
Konjkav, M., Kavianpour, M., Vatandoust, H. & Khosrojerdi, A. (2016a). Numerical analysis of the geometrical performance of flip bucket spillway on hydraulic parameters and cavitation phenomenon. Third International Conference on Modern Research in Civil Engineering, Architecture, Urban Management and the Environment. (in Persian)
Konjkav, M., Kavianpour, M., Vatandoust, H. & Khosrojerdi, A. (2016b). Numerical simulation of the performance of the geometric configuration of the flip bucket spillway on the energy dissipation of two-phase flow ski jumping. The second international conference on man, architecture, civil engineering and the city, ICOHACC02_150.6. (in Persian)
Mansouri, R., Moafi, F., Beheshtirad, M. & Karbakhsh, A. (2019). Investigation of Hydraulic properties in Flip Bucket Using Numerical Model. Journal of Irrigation and Water Engineering, 10(2), 1-12 (in Persian)
Mollazadeh, A, Azizyan, Gh. R. & Beirami, M.K. (2020). Energy Dissipation of Converged Ski-jump Buckets by using Dividing Wall. Amirkabir Journal of Civil Engineering, 53(5), 489-492
Navaei, B, Akhtari, AA. & Daneshfaraz, R. (2016). Experimental Study of Flip Bucket Effect at the End of Ogee Spillway on Energy Dissipation and Jet Length, The Journal of Water and Soil Science, 26(3-2), 133-142
Omidvarinia, M. & Musavi-Jahromi, H. (2012). Effect of approach length and angle of ski jump on the outlet trajectory. Journal of Water and Soil Resources Conservation1(4), 1-18. (in Persian)
Sadeghi Askari, M., Mousavi, H. & Ghomeshi, M. (2016). Investigation the Effect of Wedge-Shaped Deflector Length and Angle in Energy Dissipation on the Flip Bucket Spillway. Journal of Irrigation Sciences and Engineering, 39(4), 225-235. (in Persian)
Saki, N. & Shafaei Bejestan, M., (2022). Experimental Investigation of the Wedge-Shaped Deflector Installation Position Effects on the Flip Bucket Spillway Energy Dissipation. Journal of Hydraulics, 17(2), 87-106. (in Persian)
Vatandoust, H., Khosrowjerdi, A. & Kavianpour, M.R. (2007a). Investigating the probability of Cavitation considering Dynamic Pressures in Flip Bucket. 6th Iranian Hydraulic Conference - Shahrekord, Iran, IHC06_170. (in Persian)
Vatandoust, H., Khosrowjerdi, A. & Kavianpour, M.R. (2007b). Examining the Pressure Fluctuations Coefficients in Flip Bucket Spillways. - 3rd National Congress on Civil Engineering – Tabriz, Iran. (in Persian)
Vatandoust, H., Khosrowjerdi, A. & Kavianpour, M.R. & Manshouri, M. (2012). The Impact of Froude Number on Pressure Fluctuations over Flip Bucket Spillways. World Applied Sciences Journal16(3), 397-402.
Vatandoust, H., Yarmohammadi, H. & Kavianpour, M.R. (2021). Investigation of supercritical flow and shape of flip bucket spillways on coefficients of dynamic pressure. Journal of Energy Resources Technology143(6), 061301, 1115/1.4048524.
Vatandoust, H., Yarmohammadi, H.R. & Aliyari, T. (2022). Investigation of Hydraulic conditions and shape of flip bucket spillways on Cavitation phenomenon by considering dynamic pressures. Journal of Energy Resources Technology, 145(4), 043102.