Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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The estimation of friction coefficient by using entropy theory in open channels

엔트로피 이론에 의한 개수로 마찰계수 산정

  • Choo, Tai Ho (Dept. of Environmental and civil Engineering, Pusan National University) ;
  • Kwak, Kil Sin (Dept. of Environmental and civil Engineering, Pusan National University) ;
  • Yun, Gwan Seon (Dept. of Environmental and civil Engineering, Pusan National University) ;
  • Yoon, Hyeon Cheol (Dept. of Environmental and civil Engineering, Pusan National University)
  • 추태호 (부산대학교 사회환경시스템공학부) ;
  • 곽길신 (부산대학교 사회환경시스템공학부) ;
  • 윤관선 (부산대학교 사회환경시스템공학부) ;
  • 윤현철 (부산대학교 사회환경시스템공학부)
  • Received : 2014.12.26
  • Accepted : 2015.04.09
  • Published : 2015.04.30
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Abstract

Both the friction velocity and the friction coefficient have to be estimated to determine flow characteristic in an open channel. In spite of the importances in an open channel, the complete interpretation is highly difficult because of free water surface, the complex of cross section and the various hydraulic parameters. The researches related to the friction factor are based on empirical outcome. Therefore, the equations are difficult to be generally applied. For that reason, the new friction factor estimation equation using the entropy concept was proposed in the present study, and the data measured in rectangular and trapezoid cross sections was used to verify the accuracy of equation. The advantage of the proposed equation dose not use the energy slope term which is difficult to be measured and to be estimated in an open channel. In addition, the proposed method showed that the accurate friction factor f can be estimated on the Basis of theoretical background.

개수로의 흐름 특성을 결정짓는 중요한 요소 중 하나는 흐름의 저항을 나타내는 마찰속도와 마찰계수이다. 하지만 개수로 흐름에서는 그 중요성에도 불구하고 자유수면과 단면의 복잡함, 다양한 수리변수들에 의해서 완벽한 해석이 매우 어렵다. 마찰계수에 대한 연구는 경험적 실험결과에 의존하고 있으므로 손쉬운 적용이 쉽지 않다. 따라서 본 연구에서는 엔트로피 개념을 활용하여 새로운 마찰계수 산정 공식을 제안하고 공식의 정확성을 증명하기 위해서 사다리꼴과 사각단면을 가진 개수로 실험 자료를 사용하였다. 본 공식의 장점은 무엇보다도 개수로에서 정확한 값을 알기 어려운 에너지 경사 항을 사용하지 않는 것에 있다. 그리고 이론적 배경을 바탕으로 높은 정확성을 가진 마찰계수 f의 산정이 가능함을 보여주었다.

Keywords

References

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