• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.61-68
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• 2021

Movable weirs with multi-stage control are necessary in many Korean rivers to actively control the water storage level. A mesh dependency test was performed to determine the appropriate number of meshes for structural analysis of movable weirs. The standing angles of movable weirs were set to 60°, 45°, 30°, and 15° for stress analysis. The standing angle of 0° was excluded from the analysis because it was unloaded. Changes in the standing angle led to changes in the water depth, maximum pressure, maximum strain, and maximum stress. The maximum average stress and the structural safety of the multi-stage control movable weir were computed and tested using the Ansys FEA software package.

• Journal of Korea Water Resources Association
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• v.51 no.9
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• pp.795-802
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• 2018

This study investigates the hydraulic characteristics and the delta development processes in the improved-pneumatic-movable weir by considering the standing angle of the weir through laboratory experiments. The delta migration speed decreases rapidly with time. As the ratio of delta height to water depth increases, the dimensionless delta migration speed decreases at the delta point. Therefore, the water depth decreases as the delta height increases. Although the delta volume is large due to the effective height of the delta, the delta migration speed and sediment deposition decreases because of the backwater effect on the delta. On the same bed slope condition, the larger the weir height, the larger the delta volume and the ratio of delta height to delta front length is close to 1.0. The delta development could be suppressed when the weir is high. Therefore, the condition that the weir is high has the suppressing effect on the delta developments.

• Journal of Korea Water Resources Association
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• v.49 no.7
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• pp.615-623
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• 2016

This Study calculated the Submerged Flow Characteristics and Discharge coefficient by the rising angular change of the Improved-Pneumatic-Movable. According to the result, the smaller the ratio of weir height and weir length (L/W) or the weir standing angle, the bigger of the downstream head ($H_2$). The change of discharge reduction factor ($Q_s/Q_1$), by the hight from weir crest to downstream surface and the ratio form weir crest to upstream water height ($h_t/H$), was decreased when the $h_t/H$ closed to number 1. Although the weir water depth of the down-stream was shallower level than the up-stream, the velocity was faster then before. And the more the flow, the less the gab between the upper and lower reaches level. And when the same flow condition, the downstream head ($H_2$) was increased when the L/W was bigger. The Submerged Flow Discharge coefficient of Improved-Pneumatic-Movable weir was made by the upstream approach flow head and the upper lower stream flow condition, not by the physical data of Movable weir.

• Journal of Korea Water Resources Association
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• v.47 no.11
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• pp.1007-1015
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• 2014

This study investigates the discharge coefficient of Improved-Pneumatic-Movable (IPM) weir through the weir, a kind of movable weirs, to estimate much more accurate rating curves using laboratory flume experiments. The discharge coefficient ($C_d$) is from 0.613 to 0.634 by the stand-up angle of the weir. The upstream Froude Number ($F_{r1}$), relative crest length(${\xi}$), Headwater Ratio ($H_1/W$), the Overflow depth ratio of weir crest ($y_c/y_1$) was changed by the upstream. And the downstream Froude number ($F_{r2}$), the Overflow depth ratio of weir crest and Downstream Water depth ($y_c/y_2$) was changed by the downstream. The ratio of Downstream and Up and Downstream water Depth (${\Delta}y/y_2$) was found to be changed by both of the up and downstream flow. They considered the major influence variables and derived the Discharge coefficient Formula at this study. The Discharge coefficient of the Improved-Pneumatic-Movable (IPM) weir was settled by the height of the Movable weir, that is to say, it was settled by the flow conditions of upstream approach flow head and physical data according to the standing angle.