• Journal of Korea Water Resources Association
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• v.39 no.4 s.165
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• pp.313-320
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• 2006

In this study, hydraulic characteristics of thalweg line occurred near the single groyne and recirculation zone around downstream of the structure were discussed from the experiments which conducted in fixed flat-bed channel flume. The thalweg line is the stream line where the maximum velocity occurs and flow separation appeared at the tip of groyne changes the thalweg alignment. In this study, the variations in flow fields which were caused by different length and permeability of groyne were measured by LSPIV(Large Scale Particle Image Velocimetry), and also the characteristics of thalweg line and separation area were analyzed. From these results, it is found that length to thalweg line from the channel wall $T_{CL}$ and height of separation area $S_h$ vary the channel width up to 75%, 50% in the change of length and permeability of groyne, however the Froude number does not affect on $T_{CL}$ and $S_h$. Velocity along the thalweg $U_{CL}$ Increased by twice the mean velocity, and the maximum velocity occurred in downstream where the distance $5{\sim}6$ times of groyne length away from the groyne, which does not get affected by length and permeability of groyne and Froude number.

• Journal of Korea Water Resources Association
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• v.38 no.2
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• pp.143-153
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• 2005

Recently, the concern of groynes that provide us with various ecological environment and improvement of scenary near river as well as hydraulic improvement has greatly increased for naturalized river and ecological river restoration. However there is no adequate design guidelines in Korea. Furthermore there is lack of research for installation of groynes in Korea. Thus, in this study, we have conducted hydraulic modeling test for kinds of groyne and changes of permeability and made a study of the analysis for installation factor of groyne. Experimental conditions were the fixed bed model for flow pattern of groyne tip and separation length about changes of groyne length and permeability. The Experiments were conducted to measure velocity and drift angle at groyne tip. The main study kas measured the groyne tip velocity for a factor of scour and drift angle for velocity increase at center of channel. We have suggested the equation about groyne tip velocity rate(tip velocity/ approach velocity) and area rate(groyne area/ flow area). And In recirculation zone of groyne downstream, To study the basic data of groyne about installation interval has analyzed the change of separation length and incidence angle. We have suggested the equation about separation length rate(separation length/ groyne length), changes of permeability and installation angle.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1126-1127
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• 2005