@article {
author = {Parsi, Ehsan and Zeinali, Masoumeh and Allahdadi, Kazem and Ansari Ghojghar, Mohammad},
title = {Prediction of Discharge for Arced Labyrinth Weirs with Trapezoidal Cross Section},
journal = {Journal of Hydraulics},
volume = {15},
number = {4},
pages = {65-79},
year = {2020},
publisher = {Iranian Hydraulic Association},
issn = {2345-4237},
eissn = {2645-8063},
doi = {10.30482/jhyd.2020.250984.1477},
abstract = {Labyrinth weirs are among the hydraulic structures that are constructed to regulate the water level and control the flow in canals, rivers and reservoirs of dams. This structure is designed to transmit large currents in low heads by increasing the effective length of the overflow crown. The crest axis of this type of weirs is indirect and in showing the horizontal surface, the overflow is composed of interconnected walls. Labyrinth weirs are repeated with triangular, trapezoidal, rectangular and arc geometries alternating in flow width. The main criterion in the labyrinth design of the weirs was to increase the flow transmission capacity on the overflow with a fixed canopy and for a certain height of the water level upstream of the weir. In this study, 145 laboratory data were used, including four types of arc labyrinth weirs with different arc radius and tangent lengths. The discharge efficiency was introduced as a dimensionless parameter using dimensional analysis. The relationships between and the critical depth of flow (y_C/P) were obtained using graphs for two different types, R2 = 0.983 and R2 = 0.998. Then a graph to y_(C_Lt )/P and H_t/P a relation to calculate the critical depth were presented. The results showed that the calculated flow rate obtained using yc is consistent with laboratory values so that the relationship between them is R2 = 0.982.Labyrinth weirs are among the hydraulic structures that are constructed to regulate the water level and control the flow in canals, rivers and reservoirs of dams. This structure is designed to transmit large currents in low heads by increasing the effective length of the overflow crown. The crest axis of this type of weirs is indirect and in showing the horizontal surface, the overflow is composed of interconnected walls. Labyrinth weirs are repeated with triangular, trapezoidal, rectangular and arc geometries alternating in flow width. The main criterion in the labyrinth design of the weirs was to increase the flow transmission capacity on the overflow with a fixed canopy and for a certain height of the water level upstream of the weir. In this study, 145 laboratory data were used, including four types of arc labyrinth weirs with different arc radius and tangent lengths. The discharge efficiency was introduced as a dimensionless parameter using dimensional analysis. The relationships between and the critical depth of flow (y_C/P) were obtained using graphs for two different types, R2 = 0.983 and R2 = 0.998. Then a graph to y_(C_Lt )/P and H_t/P a relation to calculate the critical depth were presented. The results showed that the calculated flow rate obtained using yc is consistent with laboratory values so that the relationship between them is R2 = 0.982.Labyrinth weirs are among the hydraulic structures that are constructed to regulate the water level and control the flow in canals, rivers and reservoirs of dams. This structure is designed to transmit large currents in low heads by increasing the effective length of the overflow crown. The crest axis of this type of weirs is indirect and in showing the horizontal surface, the overflow is composed of interconnected walls. Labyrinth weirs are repeated with triangular, trapezoidal, rectangular and arc geometries alternating in flow width. The main criterion in the labyrinth design of the weirs was to increase the flow transmission capacity on the overflow with a fixed canopy and for a certain height of the water level upstream of the weir. In this study, 145 laboratory data were used, including four types of arc labyrinth weirs with different arc radius and tangent lengths. The discharge efficiency was introduced as a dimensionless parameter using dimensional analysis. The relationships between and the critical depth of flow (y_C/P) were obtained using graphs for two different types, R2 = 0.983 and R2 = 0.998. Then a graph to y_(C_Lt )/P and H_t/P a relation to calculate the critical depth were presented. The results showed that the calculated flow rate obtained using yc is consistent with laboratory values so that the relationship between them is R2 = 0.982.Labyrinth weirs are among the hydraulic structures that are constructed to regulate the water level and control the flow in canals, rivers and reservoirs of dams. This structure is designed to transmit large currents in low heads by increasing the effective length of the overflow crown. The crest axis of this type of weirs is indirect and in showing the horizontal surface, the overflow is composed of interconnected walls. Labyrinth weirs are repeated with triangular, trapezoidal, rectangular and arc geometries alternating in flow width. The main criterion in the labyrinth design of the weirs was to increase the flow transmission capacity on the overflow with a fixed canopy and for a certain height of the water level upstream of the weir. In this study, 145 laboratory data were used, including four types of arc labyrinth weirs with different arc radius and tangent lengths. The discharge efficiency was introduced as a dimensionless parameter using dimensional analysis. The relationships between and the critical depth of flow (y_C/P) were obtained using graphs for two different types, R2 = 0.983 and R2 = 0.998. Then a graph to y_(C_Lt )/P and H_t/P a relation to calculate the critical depth were presented. The results showed that the calculated flow rate obtained using yc is consistent with laboratory values so that the relationship between them is R2 = 0.982.},
keywords = {labyrinth weirs,Discharge Efficiency,Hydraulic Model,Regression},
title_fa = {پیش بینی دبی عبوری سرریزهای زیگزاگی قوسی با مقطع ذوزنقه ای},
abstract_fa = {سرریزهای زیگزاگی از جمله سازههای هیدرولیکی هستند که جهت تنظیم سطح آب وکنترل جریان در کانالها، رودخانهها و مخازن سدها احداث میشوند. این سازه، برای انتقال جریانهای بزرگ در هدهای کم، با افزایش طول مؤثر تاج سرریز، طراحی میگردد. محور تاج این نوع سرریزها، به صورت غیر مستقیم بوده و در نمایش سطح افقی، سرریز از دیوارههای متصل به هم تشکیل شده است. سرریزهای زیگزاگی با هندسه مثلثی، ذوزنقهای، مستطیلی و قوسی با تناوب در عرض جریان تکرار میگردد. معیار اصلی در طراحی زیگزاگی سرریزها، افزایش ظرفیت انتقال جریان روی سرریز با تاج ثابت و به ازای ارتفاع معین سطح آب در بالادست سرریز بوده است. در این تحقیق از 145 داده آزمایشگاهی، شامل چهار تیپ سرریز زیگزاگی قوسی با شعاع قوس و طول تانژانت مختلف استفاده شد. ضریب دبی به صورت پارامتر بیبعد با استفاده از آنالیز ابعادی معرفی گردید. روابط بین و عمق بحرانی جریان ( ) با استفاده از ترسیم نمودار مربوطه برای دو تیپ متفاوت و 983/0 R2= و 998/0 R2= بدست آمد. سپس با ترسیم نمودار مربوط به و رابطهای برای محاسبه عمق بحرانی ارائه شد. نتایج نشان داد که مقدار دبی محاسباتی با استفاده از yc بدست آمده، با مقادیر آزمایشگاهی همخوانی دارد به طوری که رابطه بین آنها دارای 982/0 R2= است.},
keywords_fa = {سرریز زیگزاگی,ضریب دبی,مدل هیدرولیکی,رگرسیون},
url = {http://jhyd.iha.ir/article_119858.html},
eprint = {http://jhyd.iha.ir/article_119858_2f0e591d7951b6b27eea5326e33a77ee.pdf}
}