The Estimation of Friction Velocity by Hydraulic Parameters Reflecting Turbulent Flow Characteristics in a Smooth Pipe Line

매끄러운 관수로 내 난류흐름특성을 반영한 수리학적 매개변수에 의한 마찰속도의 산정

  • Received : 2016.02.04
  • Accepted : 2016.04.01
  • Published : 2016.04.28


Grid(pipe network) design is an important element of Smart Water Grid, which essential to estimate hydraulic parameters such as the pressure, friction factor, friction velocity, head loss and energy slope. Especially, friction velocity in a grid is an important factor in conjunction with energy gradient, friction coefficient, pressure and head loss. However, accurate estimation friction head loss, friction velocity and friction factor are very difficult. The empirical friction factor is still estimated by using theory and equation which were developed one hundred years ago. Therefore, in this paper, new equation from maximum velocity and friction velocity is developed by using integration relationship between Darcy-Weisbach's friction head loss equation and Schlichting equation and regression analysis. To prove the developed equation, smooth pipe data areis used. Proposed equation shows high accuracy compared to observed data. Study results are expected to be used in stability improvements and design in a grid.


Friction Velocity;Friction Factor;Smooth Pipeline;SWG;Turbulent Flow


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