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Nihat Kaya - One of the best experts on this subject based on the ideXlab platform.
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discharge coefficient of a semi elliptical side Weir in subcritical flow
Flow Measurement and Instrumentation, 2011Co-Authors: Nihat Kaya, Emin M Emiroglu, Hayrullah AgacciogluAbstract:Abstract A labyrinth Weir is an overflow Weir, folded in plan view to provide a longer total effective length for a given overall Weir width. The total length of the labyrinth Weir is typically three to five times the Weir width. In this study, a semi-elliptical labyrinth Weir was used as a side Weir structure. Rectangular side Weirs have attracted considerable research interest. The same, however, is not true for labyrinth side Weirs. The present study investigated the hydraulic effects of semi-elliptical side Weirs in order to increase their discharge capacity. To estimate the outflow over a semi-elliptical side Weir, the discharge coefficient in the side Weir equation needs to be determined. A comprehensive laboratory study including 677 tests was conducted to determine the discharge coefficient of the semi-elliptical side Weir. The results were analyzed to find the influence of the dimensionless Weir length L / B , the dimensionless effective length L / l , the dimensionless Weir height p / h 1 , the dimensionless ellipse radius b / a , and upstream Froude number F 1 on the discharge coefficient. It was found that the discharge coefficient of semi-elliptical side Weirs is higher than that of classical side Weirs. Additionally, a reliable equation for calculating the discharge coefficient of semi-elliptical side Weirs is presented.
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discharge coefficient for trapezoidal labyrinth side Weir in subcritical flow
Water Resources Management, 2011Co-Authors: Muhammet Emin Emiroglu, Nihat KayaAbstract:The discharge coefficient of a trapezoidal labyrinth side Weir is a function of the Froude number F 1 , the dimensionless effective crest length L/l, the dimensionless Weir length L/B, the dimensionless Weir height p/h 1 , and the sidewall angle α. A labyrinth Weir is an overflow Weir, folded in plan view to provide a longer total effective length for a given overall Weir width. These Weirs have advantages compared to the straight overflow Weir and the standard ogee crest. Previous studies on the subject have generally focused on rectangular side Weirs located on a straight channel. The present study investigates the hydraulic behavior of a trapezoidal labyrinth side Weir. The results show that the discharge coefficient of labyrinth side Weirs gives a significantly higher coefficient value compare to that of conventional straight side Weirs. Discharge coefficient of the trapezoidal labyrinth side Weir is 1.5 to 5.0 times higher than the conventional straight side Weir. Consequently, an equation for the coefficient of discharge is introduced. The results predicted by the equation were shown to be very satisfactory using root mean square error (RMSE), mean absolute error (MAE) and correlation coefficient (R) statistics. Copyright Springer Science+Business Media B.V. 2011
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discharge coefficient for trapezoidal labyrinth side Weir in subcritical flow
Water Resources Management, 2011Co-Authors: Muhammet Emin Emiroglu, Nihat KayaAbstract:The discharge coefficient of a trapezoidal labyrinth side Weir is a function of the Froude number F1, the dimensionless effective crest length L/l, the dimensionless Weir length L/B, the dimensionless Weir height p/h1, and the sidewall angle α. A labyrinth Weir is an overflow Weir, folded in plan view to provide a longer total effective length for a given overall Weir width. These Weirs have advantages compared to the straight overflow Weir and the standard ogee crest. Previous studies on the subject have generally focused on rectangular side Weirs located on a straight channel. The present study investigates the hydraulic behavior of a trapezoidal labyrinth side Weir. The results show that the discharge coefficient of labyrinth side Weirs gives a significantly higher coefficient value compare to that of conventional straight side Weirs. Discharge coefficient of the trapezoidal labyrinth side Weir is 1.5 to 5.0 times higher than the conventional straight side Weir. Consequently, an equation for the coefficient of discharge is introduced. The results predicted by the equation were shown to be very satisfactory using root mean square error (RMSE), mean absolute error (MAE) and correlation coefficient (R) statistics.
Muhammet Emin Emiroglu - One of the best experts on this subject based on the ideXlab platform.
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discharge coefficient for trapezoidal labyrinth side Weir in subcritical flow
Water Resources Management, 2011Co-Authors: Muhammet Emin Emiroglu, Nihat KayaAbstract:The discharge coefficient of a trapezoidal labyrinth side Weir is a function of the Froude number F 1 , the dimensionless effective crest length L/l, the dimensionless Weir length L/B, the dimensionless Weir height p/h 1 , and the sidewall angle α. A labyrinth Weir is an overflow Weir, folded in plan view to provide a longer total effective length for a given overall Weir width. These Weirs have advantages compared to the straight overflow Weir and the standard ogee crest. Previous studies on the subject have generally focused on rectangular side Weirs located on a straight channel. The present study investigates the hydraulic behavior of a trapezoidal labyrinth side Weir. The results show that the discharge coefficient of labyrinth side Weirs gives a significantly higher coefficient value compare to that of conventional straight side Weirs. Discharge coefficient of the trapezoidal labyrinth side Weir is 1.5 to 5.0 times higher than the conventional straight side Weir. Consequently, an equation for the coefficient of discharge is introduced. The results predicted by the equation were shown to be very satisfactory using root mean square error (RMSE), mean absolute error (MAE) and correlation coefficient (R) statistics. Copyright Springer Science+Business Media B.V. 2011
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discharge coefficient for trapezoidal labyrinth side Weir in subcritical flow
Water Resources Management, 2011Co-Authors: Muhammet Emin Emiroglu, Nihat KayaAbstract:The discharge coefficient of a trapezoidal labyrinth side Weir is a function of the Froude number F1, the dimensionless effective crest length L/l, the dimensionless Weir length L/B, the dimensionless Weir height p/h1, and the sidewall angle α. A labyrinth Weir is an overflow Weir, folded in plan view to provide a longer total effective length for a given overall Weir width. These Weirs have advantages compared to the straight overflow Weir and the standard ogee crest. Previous studies on the subject have generally focused on rectangular side Weirs located on a straight channel. The present study investigates the hydraulic behavior of a trapezoidal labyrinth side Weir. The results show that the discharge coefficient of labyrinth side Weirs gives a significantly higher coefficient value compare to that of conventional straight side Weirs. Discharge coefficient of the trapezoidal labyrinth side Weir is 1.5 to 5.0 times higher than the conventional straight side Weir. Consequently, an equation for the coefficient of discharge is introduced. The results predicted by the equation were shown to be very satisfactory using root mean square error (RMSE), mean absolute error (MAE) and correlation coefficient (R) statistics.
Blake P Tullis - One of the best experts on this subject based on the ideXlab platform.
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Geometric Effects on Discharge Relationships for Labyrinth Weirs
Journal of Hydraulic Engineering, 2020Co-Authors: Blake P Tullis, B. M. Crookston, Jillian Brislin, Tyler SeamonsAbstract:AbstractPublished labyrinth Weir design methods, along with specific site constraints, are typically used to develop an appropriate labyrinth Weir geometry (footprint, Weir height, wall thickness, ...
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Piano Key Weir Hydraulics and Labyrinth Weir Comparison
Journal of Irrigation and Drainage Engineering, 2013Co-Authors: Robyn Anderson, Blake P TullisAbstract:A piano key (PK) Weir is a type of nonlinear (labyrinth-type) control structure with a relatively small spillway footprint. No standard PK Weir design procedure is available, and the amount of published information on PK Weirs is limited. PK Weirs have a large number of geometric parameters that can affect head-discharge performance. A PK Weir geometric design has, however, been recommended in the literature, along with a head-discharge relationship specific to that PK Weir geometry. To develop a better understanding of the effects of PK Weir geometry on discharge efficiency, nine laboratory-scale four-cycle PK Weir configurations were tested (including the recommended design). The effects of the following PK Weir geometry or modifications on Weir performance were partially isolated: varying the inlet-to-outlet key ratio, raising the crest via a parapet wall, rounding the upstream apex walls, and varying the crest type. The appropriateness of the recommended head-discharge equation specific to the recommended design was evaluated, and the relative head-discharge efficiency of trapezoidal labyrinth and PK Weirs with respect to footprint restrictions and crest length were compared.
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piano key Weir submergence in channel applications
Journal of Hydraulic Engineering, 2012Co-Authors: M R Dabling, Blake P TullisAbstract:AbstractWeir submergence can influence head-discharge relationships for Weirs used in channel applications when high tailwater conditions exist owing to a downstream control. Weir submergence describes a condition in which the water level downstream of the Weir exceeds the Weir crest elevation. When a Weir becomes submerged, the driving head required to pass a specific discharge over the Weir can increase significantly relative to a free-flow condition. In this study, the effects of tailwater submergence on laboratory-scale piano key Weir head-discharge relationships were evaluated experimentally and compared with previously published data for labyrinth and sharp-crested linear Weir submergence. The results of this comparison show that for relatively low levels of submergence, the piano key Weir requires less upstream head relative to the labyrinth Weir to pass a given discharge. This increase in efficiency was minimal (<6%) and was reversed at higher submergence levels.
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discharge efficiency of reservoir application specific labyrinth Weirs
Journal of Irrigation and Drainage Engineering-asce, 2012Co-Authors: B. M. Crookston, Blake P TullisAbstract:AbstractPublished labyrinth Weir design methods, which have primarily been developed on the basis of labyrinth Weir test data from laboratory flumes, are specific to in-channel labyrinth Weir applications in which the approach flow is oriented normal to the Weir axis. Consequently, some uncertainty exists regarding the hydraulic performance of labyrinth Weir configurations that are specific to reservoir applications (i.e., projecting, flush, rounded inlet, and arced labyrinth Weirs). The discharge efficiency, as characterized by the Weir discharge coefficient, of laboratory-scale projecting, flush, rounded inlet, and arced labyrinth Weirs with 12 degree sidewall angles, were evaluated as a function of HT/P and compared with in-channel labyrinth Weir discharge efficiencies. The arced labyrinth Weir configuration had a higher discharge efficiency (∼5 –11% higher than an in-channel labyrinth Weir orientation). In general, the projecting, flush, and rounded inlet orientations were less efficient than the in...
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comparison of piano key and rectangular labyrinth Weir hydraulics
Journal of Hydraulic Engineering, 2012Co-Authors: Robyn Anderson, Blake P TullisAbstract:AbstractThe piano key or PK Weir represents a relatively new hydraulic structure in both research and practice. There is currently a limited understanding regarding the influence of the large number of PK Weir geometric parameters on hydraulic performance. A specific PK Weir design configuration, suggested to be highly efficient, has been presented in the literature. By using laboratory-scale physical models, the hydraulic efficiency of the recommended PK Weir design was compared with that of a geometrically comparable rectangular labyrinth Weir, with and without sloping floors (consistent with the PK Weir geometry) installed in the inlet and outlet keys or cycles. In general, the test data showed that the PK Weir was more efficient than the geometrically comparable rectangular labyrinth Weir, a fact likely attributable to a reduction in entrance losses associated with the PK Weir inlet key geometry.
J.h. Kim - One of the best experts on this subject based on the ideXlab platform.
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Hydraulic characteristics by Weir type in a pool-Weir fishway
Ecological Engineering, 2001Co-Authors: J.h. KimAbstract:Abstract This study deals with hydraulic characteristics for different Weir types and effects on upstream migration of fish in a pool-Weir fishway, and presents an optimal design of Weir for an easy upstream migration. Experiments were performed to estimate hydraulic conditions for different Weir types to determine the overall performance of the Weir tested. The results showed that a rectangular Weir with a notch installed in a straight configuration was preferable to one in a zigzag configuration or to a trapezoidal Weir, since it made the flow stable and created a resting place for fish in the pool and thus made it possible for the upstream migration of fish.
D. Z. Zhu - One of the best experts on this subject based on the ideXlab platform.
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Physical modelling of pool and Weir fishways with rock Weirs
River Research and Applications, 2017Co-Authors: C. Kupferschmidt, D. Z. ZhuAbstract:The flow characteristics of pool and Weir fishways with rock Weirs were studied through physical modelling. Detailed flow measurements were obtained using an acoustic Doppler velocimeter to understand how Weir geometry, discharge, and bed slope affect flow patterns, velocity, turbulence kinetic energy, turbulence intensity, and Reynolds shear stresses in the fishway. The Weir geometries used in this study are similar to those typically used for river restoration projects. The use of a V-shaped rock Weir was found to reduce the mean streamwise velocity in the pools by about 20% but more than double the maximum velocity magnitude. Two stage–discharge relationships were developed using the standard Weir equation and a modified discharge coefficient to account for both flow over the Weir and orifice flow through the base of the Weir. The use of V-shaped rock Weirs has the potential to offer significant advantages in assisting multispecies fish migration. The results of this study can be applied to the hydrotechnical design of pool and Weir fishways with rock Weirs and for river restoration projects.
