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Analysis of Overflow Characteristics around a Circular-Crested Weir by Using Numerical Model

수치모의를 이용한 원형위어의 월류흐름 특성 해석

Kim, Dae-Geun
김대근

  • Received : 2014.12.03
  • Accepted : 2016.03.02
  • Published : 2016.04.15

Abstract

The present study used the hydrodynamic numerical model, with the Reynolds-averaged Navier-Stokes equations (RANS) as its governing equations, to analyze overflow characteristics such as the discharge coefficient of circular-crested weir and the flow velocity and pressure distribution of weir crest. The simulation results well reproduced the overflow characteristics of the overfall of circular-crested weir both qualitatively and quantitatively. As for the discharge coefficient, rational results were yielded by the discharge coefficient equation proposed by Hager(1985) in the $H_1/R_b<0.58$ and by the discharge coefficient equation proposed by Samani and Bagheri(2014) in the $H_1/R_b>0.58$, respectively. Because most existing discharge coefficient equations were developed by disregarding the effects of the approach velocity, when they are applied, it is necessary to evaluate the effects of the approach velocity on the overflow head beforehand.

Keywords

circular-crested weir;discharge coefficient;overflow head;RANS;weir crest

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