Trapez Kanallarda Savak Kapağı ve Savaklarla Enerji Azaltımının Deneysel ve Sayısal Analizi

Year 2022, , 156 - 169, 23.02.2022

Ercan Gemici , Numan Kocaman Tuğba Vural , Mert Züngör

https://doi.org/10.47495/okufbed.1036997

Abstract

In open channels, only one of the sluice gates or weirs is often used for regulation purposes to limit the acceleration of flow through the channel and to help reduce the forces around the water structures. When the sluice gates are used single, depending on the tail water depth and the gate opening, all cases might experience free or submerged flow conditions and hydraulic jump might occur at the downstream. In this case, it is possible to damage the submerged or semi-submerged structures in this area due to the high flow velocity and high hydraulic energy at the downstream of the gate. The combination of weirs and gates can be preferred both to preserve the stability of the river bottom and to prevent damage to structures such as submerged pipes and transmission lines stretching across cross-sectional direction. In this study, the variation of the flow characteristics in the channel and around the pipeline extending across the channel cross-section was investigated when varying cross-sections weirs with the sluice gate are used together. Experimental flow velocity and level measurements were carried out under different discharge conditions. These measurements were used to determine the boundary conditions of the computational fluid dynamics (CFD) software and to verify the flow property values obtained by CFD. After the verification, the velocity, pressure and specific hydraulic head values of the points that could not be measured experimentally with CFD software were also obtained. As a result of both experimental and numerical analysis, it has been seen that hydraulic head can be reduced significantly by using the gate and weir structures together. With the increasing discharge, the effect of the weir geometries on energy dissipation emerges clearly. By using the two structures together, both the water depth in open channels will be kept at the desired level and possible damage due to water forces acting on underwater structures will be prevented.

Keywords

Energy dissipation, Open channel, Velocity, Sluice gate, Weir

Experimental and Numerical Analysis of Energy Dissipation with Sluice Gate and Weirs in Trapezoidal Channel

Abstract

Açık kanallarda kanal boyunca akışın hızlanmasını sınırlamak ve su yapıları etrafındaki kuvvetleri azaltmaya yardımcı olmak için genellikle kapak veya savaklardan yalnız biri regülasyon amacıyla kullanılmaktadır. Savak kapakları yalnız kullanıldığında, kuyruk suyu derinliğine ve kapak açıklığına bağlı olarak serbest veya batmış akış koşulları meydana gelebilir ve mansapta hidrolik sıçrama oluşabilir. Bu durumda, kapağın mansabındaki yüksek akış hızı ve hidrolik enerji nedeniyle bu bölgedeki batık veya yarı batık yapıların zarar görmesi olasıdır. Kapak ve savakların beraber kullanımı, hem nehir tabanının stabilitesinin korunması hem de en kesit boyunca uzanan batık borular ve iletim hatları gibi yapılara zarar gelmemesi için tercih edilebilir. Bu çalışmada savak kapağı ile değişen en kesitli savaklar birlikte kullanıldığında kanalın ve kanal en kesiti doğrultusunda uzanan boru hattı etrafındaki akış özelliklerinin değişimi araştırılmıştır. Deneysel akış hızı ve su seviyeleri farklı debiler için ölçülmüştür. Bu ölçümler, hesaplamalı akışkanlar dinamiği (HAD) yazılımının sınır koşullarını belirlemek ve HAD ile elde edilen akış özelliği değerlerini doğrulamak için kullanılmıştır. Doğrulamanın ardından HAD yazılımı ile deneysel olarak ölçülemeyen noktaların hız, basınç ve özgül hidrolik enerji değerleri de elde edilmiştir. Hem deneysel hem de sayısal analizler sonucunda, kapak ve savak yapılarının birlikte kullanılmasıyla hidrolik enerjinin önemli ölçüde azaltılabileceği görülmüştür. Yüksek debilerde savak geometrisinin enerji kaybı üzerindeki etkisi açıkça görülmektedir. İki yapının birlikte kullanılmasıyla hem açık kanallardaki su derinliği istenilen seviyede tutulacak hem de su altı yapılarına etki eden su kuvvetleri nedeniyle olası hasarların önüne geçilecektir.

Keywords

enerji azaltımı, açık kanal, hız

References

• Abdelmonem, YK., Shabayek, S., Khairy, AO. Energy dissipation downstream sluice gate using a pendulum sill. Alexandria Engineering Journal 2018; 57(4): 3977-3983
• Al-Khatib, IA., Gogus, M. Prediction models for discharge estimation in rectangular compound broad-crested weirs. Flow Measurement and Instrumentation 2014; 36, 1-8
• Bijankhan, M., Kouchakzadeh, S., Belaud, G. Application of the submerged experimental velocity profiles for the sluice gate's stage-discharge relationship. Flow Measurement and Instrumentation 2017; 54, 97-108
• Cassan, L., Belaud, G. Experimental and numerical investigation of flow under sluice gates. Journal of Hydraulic Engineering 2012; 138(4): 367-373
• Denys, FJ., Basson, GR. Unsteady hydrodynamic behavior at piano key weirs. Journal of Hydraulic Engineering 2020; 146(5): 04020028
• Dou, M., Qin, C., Li, G., Wang, C. Research on calculation method of free flow discharge based on artificial neural network and regression analysis. Flow Measurement and Instrumentation 2020; 72, 101707
• Erdbrink, CD., Krzhizhanovskaya, VV., Sloot, PM. Free-surface flow simulations for discharge-based operation of hydraulic structure gates. Journal of Hydroinformatics 2014; 16 (1): 189-206
• Ferro, V. Testing the stage-discharge relationship of a sharp crested sluice gate deduced by the momentum equation for a free-flow condition. Flow Measurement and Instrumentation 2018; 63, 14-17
• Habibzadeh, A., Vatankhah, AR., Rajaratnam, N. Role of energy loss on discharge characteristics of sluice gates. Journal of Hydraulic Engineering 2011; 137(9): 1079-1084
• Haghiabi, AH., Nou, MRG., Parsaie, A. The energy dissipation of flow over the labyrinth weirs. Alexandria Engineering Journal 2021; In Press
• Hoseini, P., Vatankhah, AR. Stage-discharge relationship for slide gates installed in partially full pipes. Flow Measurement and Instrumentation 2021; 77, 101838
• Hu, H., Qian, Z., Yang, W., Hou, D., Du, L. Numerical study of characteristics and discharge capacity of piano key weirs. Flow Measurement and Instrumentation 2018; 62, 27-32
• Imanian, H., Mohammadian, A., Hoshyar, P. Experimental and numerical study of flow over a broad-crested weir under different hydraulic head ratios. Flow Measurement and Instrumentation 2021; 80, 102004
• Karimi, M., Attari, J., Saneie, M., Jalili Ghazizadeh, MR. Side weir flow characteristics: comparison of piano key, labyrinth, and linear types. Journal of Hydraulic Engineering 2018; 144(12): 04018075
• Liu, SH., Liao, TT., Luo, QS. Numerical simulation of turbulent flow behind sluice gate under submerged discharge conditions. Journal of Hydrodynamics 2015; 27(2): 257-263
• Petrila, T. Mathematical model for the free surface flow under a sluice gate. Applied Mathematics and Computation 2002; 125(1): 49-58
• Ran, D., Wang, W., Hu, X. Three-dimensional numerical simulation of flow in trapezoidal cutthroat flumes based on FLOW-3D. Frontiers of Agricultural Science and Engineering 2018; 5(2): 168-176
• Sauida, MF. Calibration of submerged multi-sluice gates. Alexandria Engineering Journal 2014; 53 (3): 663-668
• Shaddehi, FR., Bijankhan, M. (2020). Experimental study on free and submerged multi-jets. Flow Measurement and Instrumentation, 75, 101805
• Shayan, HK., Farhoudi, J. Effective parameters for calculating discharge coefficient of sluice gates. Flow Measurement and Instrumentation 2013; 33, 96-105
• Silva, CO., Rijo, M. Flow rate measurements under sluice gates. Journal of Irrigation and Drainage Engineering 2017; 143(6), 06017001
• Tan, GM., Ding, ZL., Wang, CD., Yao, X. Gate regulation speed and transition process of unsteady flow in channel. Journal of Hydrodynamics 2008; 20(2): 231-238
• Tullis, BP. Behavior of submerged ogee crest weir discharge coefficients. Journal of Irrigation and Drainage Engineering 2011; 137(10): 677-681
• Vaheddoost, B., Safari, MJS., Zeynali, RI. Discharge coefficient for vertical sluice gate under submerged condition using contraction and energy loss coefficients. Flow Measurement and Instrumentation 2021; 80, 102007
• Zhang, J., Chang, Q., Zhang, QH., & Li, SN. Experimental study on discharge coefficient of a gear-shaped weir. Water Science and Engineering 2018; 11(3): 258-264
• Zounemat-Kermani, M., Mahdavi-Meymand, A. Hybrid meta-heuristics artificial intelligence models in simulating discharge passing the piano key weirs. Journal of Hydrology 2019; 569, 12-21