Study on Influence Increase Effective Length on the Hydraulic Characteristic and Discharge Coefficient in Side Weirs

Document Type : پژوهشی



One of the most important discharge control ways in hydraulic structures is side weir which is used in irrigation, water distribution, waste-water engineering, drainage, flood control and other water related projects.In order to increases Cm value and control on water surface when there is restriction in the weir length(L), side weir with different geometry is used. In present research seventhly experimental tests were conducted on the semi-circular side weir with different lengths and heights(w).Studied the influence of hydraulic and geometry variableson the Cm valueand a new equation was developed to calculate discharge coefficient of the semi-circular side weir. The results indicated Cm in the semi-circular side weir is 1.5 to 2 times morethan rectangular side weir.


1. De Marchi, G., "Sagio di teoria di fuzionamente degli stramazzi laterali. L’Elettrica, Millano, Italy", 11(11), pp. 849-860, (1934).
2. Hager, W. H. "Lateral outflow over side weirs", J Irrig Drain Eng ASCE, 113(4), pp. 491–504, (1987).
3. Subramanya, K., & Awasthy, S. C., "Spatially varied flow over side weirs", J Hydraul Div ASCE, 98(HY1), pp.1–10, (1972).
4. Yu-Tech, L., "Discussion of spatially varied flow over side weir", J Hydraul Eng ASCE, 98(11), pp. 2046–2048, (1972).
5. El-Khashab. A., and Smith. K. V. H.," Experimental investigation of flow over side weirs", J. Hydr. Engrg., ASCE, 102(9), pp. 1255-1268, (1976).
6. Ranga Raju, K. G., Prasad, B., & Grupta, S. K.,"Side weir in rectangular channels", J Hydraul Div ASCE Proc, 105(HY5), pp. 547–554, (1979).
7. Swamee. P. K., and Pathak. S. K., and Ali. S. M.," Side weir analysis using elementary discharge coefficient", J. Irrig. and Drain. Engrg., ASCE, 120(4), pp. 742-755, (1994).
8. Singh, R., Manivannan, D., & Satyanarayana, T., "Discharge coefficient of rectangular side weirs", J. Irrig Drain Eng ASCE Proc, 120(4), pp. 814–819, (1994).
9. Borghei, S.M., Jalili, M. R., & Ghodsian, M.,"Discaharge coefficient for sharp-crested side weir in subcritical flow", J. Hydraul Eng.125(10), pp.1051–1056, (1999).
10. Emiroglu, M. E., Agaccioglu, H., & Kaya, N., "Discharging capacity of rectangular side weirs in straight open channels", Flow Measurement and Instrumentation, pp. 319–330, (2011).
11. Ura, M., Kita, Y., Akiyama, J., Moriyama, H., & Kumar Jha, A., "Discharge coefficient of oblique side weirs", J. Hydroscience and Hydraulic Engrg., JSCE, 19(1), pp. 85-96, (2001).
12. نکوئی،م.،" بررسی و تعیین ضریب دبی سرریز جانبی منقاره‌ای به‌صورت آزمایشگاهی"، پایان‌نامه‌ی کارشناسی ارشد دانشگاه صنعتی شریف، (1385).
13. Borghei. S. M., Parvane. A., "Discharge characteristics of modified oblique side weir in subcritical flow", Flow Measurement and Instrumentation, 22 (2011), pp. 370–376, (2011).
14. Emiroglu, M. E., Kaya, N., & Agaccioglu, H., "Discharge capacity of labyrinth side weir located on astraight channel", J Irrig Drain Eng ASCE, 136 (1), pp. 37– 46, (2010).
15. Kaya, N., Emiroglu, M.E., & Agaccioglu, H., "Discharge coefficient of a semi-elliptical side weir in subcritisal flow", Flow Measurment and Instrumentation. 22 (1), pp.25-32, (2011).
16. Emiroglu, M. E., Kaya, N., "Discharge Coefficient for Trapezoidal Labyrinth Side Weir in Subcritical Flow",Water Resour Manage , 25, pp. 1037–1058, (2011).