Document Type : Original Article

Abstract

Sharp crested weirs and sluice gates because of their ease making, water surface control potential and flow rate measuring have been broadly studied. Since the nature of flow on the weirs is highly complicated, mostly the driven equations are taken in account a series of simplifier hypothesis that are on the base of empirical experiments. On the other hand most of the weirs cause a relatively calm zone of water on their upstream, which is a place of waste material and sediments to precipitate that is the disadvantage of the device. With gradual storage of sediments, the condition of flow changed and driven equations will lose their precision. In this case composition of weir and gate can be a useful solution for passage of floating materials over the weir and transmission of sediment materials from the lower part of the gate. In this study, hydraulic characteristics of the 18 combined model of trapezoidal weir-gate in the tree groups with three different opening gates at the end of an open channel with a circular cross section were studied. Using dimensional analysis, analytical solutions and statistical analysis, an equation for combined discharge by combined model of weir-gate was introduced and was evaluated by experimental data. The Results showed that the outcome discharge coefficient have a good agreement with experimental data.

Keywords

Ahmed, F. H. 1985. Characteristics of discharge of combined flow through sluice gate and over weirs. J. Eng. Technol. Iraq. 3, 49-63.
 
Alhamid, A. A. 1999. Analysis and formulation of flow through combined v-notch-gate-device. J. Hydraul. Res. 37, 697-705.
 
Alhamid, A. A., Husain, D. and Negm, A. M. 1996. Discharge equation for simultaneous flow over rectangular weirs and below inverted triangular weirs. Arab Gulf J. Sci. Res. 14, 595-607.
 
Alhamid, A. A., Negm, A. M. and Al-brahim, A. M. 1997. Discharge equation for proposed self-cleaning device. J. King Saud Uni. Eng. Sci. 9(1); 13-24.
 
Faghfour-Maghrebi, M. and Rezaei-Nasab, M. S. 2005. Estimation of discharge in Circular Sewage crossing using the combination model of Weir-Gate. J. Water Wastewater. 6, 55-60. (in Persian)
 
Ferro, V. 2000. Simultaneous flow over and under a gate. J. Irrig. Drain. E-ASCE. 126, 190-193.
 
French, R. H. 1987. Open Channel Hydraulic. McGraw-Hill.
 
Gharehgozlu, M., Masoodian, M., Salehi-Neishapuri, S. A. A., Naderi, F. and Suri, A. 2013. Experimental investigation of discharge coefficient in combined model of cylindrical weir-gate in small channels. J. Soil Water Conserv. 20(1): 198-185. (in Persian)
 
Hayawi, H. A., Yahia, A. A. and Hayawi, Gh. A. 2008. Free combined flow over a triangular weir and under rectangular gate. Damascus Univ. J. 24, 9-22.
 
Heidarpour, M., Razavian, S. H. and Hosseini, Y. 2014. Study of simultaneous flow over sharp-crested trapezoidal weir and below sluice gate. J. Water Soil Sci. (Sci. Technol. Agric. Nat. Resour.) 18(68): 155-147. (in Persian)
 
 
Hosseini, M. and Abrishami, J. 2006. Hydraulic of the Open Channels. 15th Ed. Astan-e-Quds Razavi Pub. (in Persian)
 
Masoodian, M., Fenderski, R. and Gharehgozlu, M. 2013. Study of discharge coefficient cylindrical weir-gate and determination of its relationship with discharge coefficient of weir and gate separately. Water Resour. Eng. J. 6, 62-51. (in Persian)
 
Masoodian, M., Gharehgozlu, M., Fenderski, R. and Naderi, F. 2014. Experimental investigation of passage flow from submerged cylindrical weir-gate in small channels. J. Soil Water Conserv. 2(3): 235-221. (in Persian)
 
Negm, A. M. 2002. Discussion of analysis and formulation of flow through combined V-Notch-Gate-Device. J. Hydraul. Res. 40, 755-765.
 
Negm, A. M., Al-brahim, A. M. and Alhamid, A. A. 2002. Combined-free flow over weirs and below gates. J. Hydraul. Res. 40, 359-365.
 
Razavian, S. H. and Heidarpour, M. 2007. Investigation of characteristics of the combined flow through a sharp rectangular weir with compressed and below a sharp rectangular weir without compaction. Proceeding of the Ninth National Seminar on Irrigation and Evapotranspiration. Jan. 4-5. Shahid Bahonar University. Kerman. Iran. (in Persian)
 
Salamati, S., Dehghani, A. A., Meftah-Halaghi, M. and Zahiri, A. R. 2015. Estimation of discharge coefficient of combined weir-gate structure by genetic programming. J. Water Soil Conserv.22(2): 255-263. (in Persian)
 
Samani, J. M. V. and Mazaheri, M. 2009. Combined flow over weir and under gate. J. Hydraul. Eng-ASCE. 135, 224-227.