Water Science and Engineering 2018, 11(3) 258-264 DOI:   https://doi.org/10.1016/j.wse.2018.09.002  ISSN: 1674-2370 CN: 32-1785/TV

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Experimental study
Discharge coefficient
Discharge capacity
Gear-shaped weir
Geometrical parameter

Experimental study on discharge coefficient of a gear-shaped weir

Jing Zhang a, Qian Chang b, Qing-hua Zhang a, *, Shu-ning Li a

a College of Water Conservancy and Civil Engineering, Shandong Agricultural University, Taian 271000, China
b River Management Bureau, Huaihe River Commission of the Ministry of Water Resources, Linyi 276000, China


This study focused on hydraulic characteristics around a gear-shaped weir in a straight channel. Systematic experiments were carried out for gears with two different heights and eight groups of geometrical parameters. The impacts of various geometrical parameters of gear-shaped weirs on the discharge capacity were investigated. The following conclusions are drawn from the experimental study: (1) The discharge coefficient () was influenced by the size of the gear: at a constant discharge, the weir with larger values of  ( is the width of the gear, and  is the width between the two neighboring gears) and (c is the height of the gear) had a smaller value of . The discharge capacity of the gear-shaped weir was influenced by the water depth in the weir. (2) For type C1 with a gear height of 0.01 m, when the discharge was less than 60 m3/h and  < 1.0 ( is the water depth at the low weir crest),  significantly increased with the discharge and ; with further increases of the discharge and ,  showed insignificant decreases and fluctuated within small ranges. For type C2 with a the gear height of 0.02 m, when the discharge was less than 60 m3/h and  < 1.0,  significantly increased with the discharge and ; when the discharge was larger than 60 m3/h and  > 1.0,  slowly decreased with the increases of the discharge and  for  ≤ 1.0 and  ≤ 1.0, and slowly increased with the discharge and  for  > 1.0 and  > 1.0. (3) A formula of  for gear-shaped weirs was established based on the principle of weir flow, with consideration of the water depth in the weir, the weir height and width, and the height of the gear.

Keywords Experimental study   Discharge coefficient   Discharge capacity   Gear-shaped weir   Geometrical parameter  
Received 2017-09-11 Revised 2018-03-19 Online: 2018-07-30 
DOI: https://doi.org/10.1016/j.wse.2018.09.002

This work was supported by the National Natural Science Foundation of China (Grant No. 51409155).

Corresponding Authors: Qing-hua Zhang
Email: zqh@sdau.edu.cn
About author:


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