Journal of the Korean Society of Fisheries and Ocean Technology (수산해양기술연구)

The Korean Society of Fisheries and Ocean Technology (한국수산해양기술학회)
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Study on the hydrodynamic coefficients of the nettings

망지의 유체역학적 계수에 관한 연구

  • Song, Dae-Ho (Department of Fisheries Physics, Graduate school, Pukyong National University) ;
  • Lee, Chun-Woo (Division of Marine Production System Management, Pukyong National University)
  • 송대호 (부경대학교 수산물리학과) ;
  • 이춘우 (부경대학교 해양생산시스템관리학부)
  • Published : 2009.03.31
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Abstract

In this study, the hydrodynamic coefficients were measured using various nettings to analyze the change of drag coefficients and lift coefficients as a basic study for deriving hydrodynamic coefficients. The data on hydrodynamic force obtained from the flume tank tests were used to compare and analyze the hydrodynamic coefficients based on Reynolds number. Standardized hydrodynamic coefficients were then assumed during the analysis procedures. The hydrodynamic coefficients were measured using the 9 kinds of nettings in which had the same total projected area with different diameters and mesh-grouping ratio. These different netting systems : mesh-grouping ratio. The results of the test of nettings were as follows; First, the drag coefficients of nettings increased when the higher attack angles applied, and decreased with the increased flow speed and netting twine diameter. Second, the lift coefficients of nettings showed the increased values until the attack angle 30 degree, but decreased for the attack angle over 40 degree. Third, the hydrodynamic coefficients of netting decreased as the Reynolds number increased, and reach at slightly states in the highest numbers. Fourth, the hydrodynamic coefficients were derived from a functional formula considering attack angles and Reynolds number, and presented in the three dimensional space.

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References

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