• Journal of Korea Water Resources Association
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• v.35 no.3
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• pp.251-259
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• 2002

Flow characteristics occurring a side-weir overflow in rectangular channel is investigated in this study. A numerical model based on the two -dimensional shallow-water equations is employed to review the factors influencing on the side- weir overflow discharge and the change of flow depths and velocities. It is found that the discharge coefficient which has the most significant influence on the overflow is affected by geometric characteristics of a side-weir, Froude number of the main channel flow and the flow depth of the main channel at the starting point of a side-weir. And the discharge coefficient applicable to a practical design of a side-weir is proposed by deriving a relationship between Froude number of the main channel flow at the starting point of a side-weir and Froude number of the main channel flow.

• Journal of Korea Water Resources Association
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• v.40 no.1 s.174
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• pp.51-62
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• 2007

To estimate more accurately the outflow over a sharp crested side weir, it is necessary to analyze the flow characteristics over side weir and to estimate the discharge coefficient in the weir equation. The purpose of this study is to estimate the discharge coefficients of sharp crested rectangular and triangular side weirs by means of hydraulic model experiments with the variations of upstream Froude number in the main channel and length and apex angle. Experimental results show that the discharge coefficients depend on the shape and geometric conditions of side weir as well as the upstream Froude number in the main channel. Through the multiple regression analysis, formulas of discharge coefficient for rectangular and triangular types are proposed and its applicability is confirmed by comparing estimated and measured discharges over side weirs.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5B
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• pp.449-458
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• 2008

This study is investigating experimentally the effect of upstream Froude number, weir height, weir length, and main channel width on the discharge coefficient of rectangular sharp crested side-weirs under subcritical flow conditions in a relatively wide rectangular open channel based on the De Marchi discharge coefficient $C_M$. The effects of four main influential parameters found by dimensional analysis, $Fr_1$, $h/y_1$, L/B, and $L/y_1$ are examined by the flume tests. New estimated equations for the discharge coefficients of sharp-crested side-weir are suggested based on the experimental results. The effect of $Fr_1$ for the discharge coefficient of sharp crested side weir is decreased in wide open channel and the relative importance of other influential parameters like $h/y_1$, L/B, and $L/y_1$ are increased. Also, the experimental results are compared with the results of other studies to extend the applicability of pre-suggested formulas for sharp-crested side-weir discharge coefficient.

• Journal of Korea Water Resources Association
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• v.43 no.6
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• pp.525-531
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• 2010

In this study, the effects of upstream Froude number ($Fr_1$), weir height (h), weir length (L), weir width (W) and main channel width (B) on the discharge coefficient of broad crested side-weirs in a relatively wide rectangular open channel were investigated experimentally. Furthermore the relationship between discharge coefficients of sharp crested side weir and broad crested side weir was studied using the concept of De Marchi discharge coefficient. The effect of $Fr_1$ on the relationship between discharge coefficients of sharp crested side weir and broad crested side weir is decreased in wide open channel and the relative importance of other influential parameters like h/$y_1$, L/B, and W/($y_1-h$) are increased. New estimated equations for the discharge coefficients of broad crested side weir are suggested from regression analysis with the experiment data sets.

• Journal of Korea Water Resources Association
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• v.44 no.12
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• pp.955-965
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• 2011

The flow characteristics of rectangular and 1 : 1 and 1 : 2 trapezoidal weirs were investigated through hydraulic experiments in order calculate the exact overflow discharge of the broad-crested side weir. The flow was found to be most stable in trapezoidal shapes with the lowest incline. The 1 : 1 and 1 : 2 trapezoidal weirs had 5.67% and 8.57% increases, respectively, compared to the rectangular weir in terms of overflow amount, which suggests that they are more effective in preventing flood. An integrated discharge coefficient equation taking into account the discharge coefficient equation and shapes was proposed through a multiple linear regression analysis with an addition of a new parameter for the side wear, $L/L_H$, to the conventional discharge coefficient equation. Also, the applicability of the newly proposed discharge coefficient equation was reviewed by comparing the measured and calculated overflow amounts based on the experimental data of preceding researches and existing researchers and the research data of this study.