Experimental study of discharge Coefficient of Piano Key Side Weir in 45-Degree Sector of a curved channel

Subject Areas : Article frome a thesis

Babak Ghobadi ¹ , Mojtaba Saneie ²

1 - M.Sc. Student, Water and Hydraulic Structures, Civil Engineering Department, University of Science & Culture, Tehran, Iran.
2 - Associate Professor, Soil Conservation and Watershed Management Research Institute, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran.

Received: 2018-05-21 Accepted : 2020-11-02 Published : 2020-10-22

Keywords: side weir, discharge coefficient, experimental investigation, piano key weir, curved channel,

Abstract :

A new type of Long-crested weirs is Piano Key weir that allows the reservoir to run at a higher level. The use of a Piano Key weir as side weir allows for more drainage, due to the geometric shape of the channel and the impact of centrifugal force on the flow, in a channel having longitudinal curvature. This research, examine the Changing of flow pattern and discharge coefficient of a Type-B Piano Key weir in 45-degree sector of a channel having longitudinal curvature by Experimental investigation. Experiments were carried out in a certain range of changes in geometric and hydraulic parameters, and the effect of each of the dimensionless parameters on the flow was determined. It is worth noting that all experiments with rectangular sharp-crested weirs have been compared. The result of this study is the high discharge coefficient of Piano Key side weir relative to the rectangular sharp-crested weir. Also, the L/b and Froude number parameters have a significant impact on the performance of the Piano Key side weir in 45-degree sector of a channel having longitudinal curvature. From other results of this research is the flow pattern that from beginning to end of the Piano Key side weir that height of the surface of the flow dropping dramatically at beginning of the weir, and eventually reaching its initial level, which is associated with lower variations in the higher heads. These deformations have been much lower when used with rectangular sharp-crested weirs.

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