Investigation of the Plan Shape Change Effect and Gate Dimension on Hydraulic Performance of Combined Models of Labyrinth Weir- Gate

Document Type : Original Article

Authors

Lecturer, Sari Agricultural Sciences and Natural Resources University, Sari, Iran

Abstract

Weir and Gate are widely used in control, diversion and measurement of flow in irrigation projects due to their simpler and relatively exact relationship. There are sediment and suspended materials in the direction of channels. The accumulation of sediments and suspended materials in the back side of weir and gate caused change of canal shape and reduction of water measurement accuracy. The combined model of weir- gate have the capability of passing settling down from under the gate and suspended materials over weir simultaneously and prevents from accumulation of sediment and suspended materials in the back side of the weir and helps to the accuracy of water measurement and passing flow. The present research investigated ten combined model of labyrinth weir- gate on the effects of plan shape change and gate height on discharge coefficient in the laboratory. The results showed that the existence of gate and increasing of opening height, increased discharge coefficient in combined model of labyrinth weir- gate. On the other hand, existence of gate in combined model of rectangular labyrinth weir- gate in low total upstream water height to weir height have higher effect on the increasing of discharge coefficient. Whereas in combined model of trapezoidal labyrinth weir- gate, with the same of total upstream water height to weir height, had uniform effect on the increasing of discharge coefficient. The results showed that increasing of upstream water height caused interference of water jets of cycles of labyrinth weir and also interference of water flow passing under the gate and flowing water over the weir. Therefore discharge coefficient was lower in deeper depths. On the other hand, in the same depth, the trapezoidal labyrinth weir had less flow interference with respect to rectangular labyrinth weir, which caused higher increase in discharge coefficient in combined model of trapezoidal

Keywords


بارانی، غ. و س. ناصری. 1382. بهینه­سازی سرریزهای کنگره­ای با استفاده از مدل­های فیزیکی. چهارمین کنفرانس هیدرولیک ایران، دانشگاه شیراز، 8ص.
حیدرپور، م.، ف. موسوی، و ع.ر. روشنی زرومهری. 1385. بررسی سرریزهای چندوجهی با پلان مستطیلی و U شکل. مجله علوم و فنون کشاورزی و منابع طبیعی، 6 (3): 61-51. 
رضایی، م. 1391. رابطه دبی- اشل در سرریزهای کنگره­ای مستطیلی. پایان­نامه کارشناسی­ارشد سازه­های آبی، دانشکده مهندسی زراعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، 69 ص.
رضویان، س.ح. و م. حیدرپور. 1386. بررسی ضریب دبی در مدل ترکیبی سرریز - دریچه لبه­تیز. ششمین کنفرانس هیدرولیک ایران، دانشگاه شهرکرد، 15-13 شهریور، شهرکرد، ایران، 8ص.
قره­گزلو، م. 1391. بررسی آزمایشگاهی جریان همزمان از مدل ترکیبی سرریز- دریچه استوانه­ای. پایان­نامه کارشناسی­ارشد سازه­های آبی، دانشکده مهندسی زراعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، 74 ص.
مسعودیان، م.، م. قره­گوزلو، ف. نادری و ن. فندرسکی. 1390. هیدرولیک جریان مستغرق در مدل ترکیبی سرریز – دریچه استوانه­ای. یازدهمین سمینار آبیاری و کاهش تبخیر، دانشگاه شهید باهنر کرمان، 20-18 بهمن، کرمان، ایران، 7ص.
یاسی، م. و م. محمدی. 1386. بررسی سرریزهای زیگزاگی با پلان قوسی. مجله علوم و فنون کشاورزی و منابع طبیعی، 11 (1)، 15-1.
Amanian, N. 1987. Performance of and design of labyrinth spillways. M.S. thesis. Utah State University, Logan, Utah.
Carollo, F. G., V. Ferro and V. Pampalone. 2010. Experimental investigation of the outflow process over a triangular labyrinth weir. Irrigation and Drainage Engineering Journal, 10-1061/(ASCE) IR.3PP.
Chanson, H. 2009. Discussion of Hydraulics of Broad-Crested Weirs with Varying Side Slopes. Irrigation and Drainage Eng. Journal, ASCE, 136:7, 508-509.
Hayawi, H. A. M., A. A. G. Yahia and G. A. M. Hayawi. 2008. Free combined flow over a triangular Weir and under rectangular gate. Damascaus University Journal, 24:1, 9-22.
Houston, K. L. and C. S. DeAngelis. 1982. A site specific study of a labyrinth spillway. Proceeding Conference on Applying Research to Hydraulic Practice, Pp: 86-95.
Israelsen, O. W. and V. E. Hanson. 1962. Irrigation Principle and Practices. 3rd. ed., New York. J. of Hydraulic Res, 37: 5697–705.
Lux, F. and D. L.Hinchliff. 1985. Design and construction of labyrinth spillway. 15th Congress of ICOLD, Lausanne, Switzerland, Pp. 249-274.
Negm, A. M., A. M. Al-Brahim, and A. A. Alhamid. 1997. Combined free flow over Weirs and below Gates.     40: 359-365.
Samani, J. M. V. and M. Mazaheri. 2009. Combined Flow over Weir and under Gate. Hydraulic Eng. Journal, 135:3, 224- 22.
Taylor, G. 1968. The performance of Labyrinth weir. Thesis presented to university of Nottingham, England.
Tullis, J. P., C .M. Wilmore and J. S. Wolfhope. 2005. Improving performance of low-head labyrinth weirs. Proc. of the 2005 World Water and Environmental Resources Congress, May 15-19, Anchorage Alaska.