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Measurements of Void Fraction of Aerated Flows over Hydraulic Structures

수공구조물에 의한 폭기 흐름의 기포분율 측정

  • Ryu, Yong-Uk (Department of Ocean Engineering, Pukyong National University) ;
  • Lee, Nam-Joo (School of Civil, Urban, and Environmental Engineering, Kyungsung University)
  • 류용욱 (부경대학교 해양공학과) ;
  • 이남주 (경성대학교 건설환경도시공학부)
  • Received : 2019.08.23
  • Accepted : 2019.08.29
  • Published : 2019.09.30

Abstract

This study carried out experimental investigation through measurements of void fraction of aerated flows generated near hydraulic structures. The imaging technique applying the shadowgraphy method was employed to quantify aeration by measuring void fractions. Aerated flows in the vicinity of a sloped weir and a stepped weir were measured using the imaging technique. Spatially distributed void fraction that was possible from gray images gives aeration rate of the flows over hydraulic structures with eco-environmental function. Aeration over the stepped weir takes place more strongly and widely in its front slope and downstream compared to the sloped weir.

본 연구는 수공구조물 주변에서 발생하는 폭기 흐름의 기포분율을 측정하는 실험 연구를 수행하였다. 그림자기법을 이용한 영상측정기법을 적용하여 기포분율을 측정하고 이를 통해 폭기 정도를 정량화하였다. 제안된 영상기법을 이용하여 경사보와 계단보 주변에서 발생하는 흐름을 측정하였다. 흑백 영상으로부터 얻어진 공간적으로 분포한 기포분율은 친환경 수공구조물 주변에서 폭기 정도를 제시할 수 있었다. 얻어진 결과로부터 계단보의 전면경사부와 하류부에서 상대적으로 강한 폭기 현상이 발생함을 알 수 있었다.

Keywords

References

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