The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
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.
Johan Hoffman - One of the best experts on this subject based on the ideXlab platform.
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Adaptive simulation of the Subcritical Flow past a sphere
Journal of Fluid Mechanics, 2006Co-Authors: Johan HoffmanAbstract:Adaptive DNS/LES (direct numerical simulation/large-eddy simulation) is used to compute the drag coefficient c D for the Flow past a sphere at Reynolds number R e = 10 4 . Using less than 10 5 mesh points, c D is computed to an accuracy of a few percent, corresponding to experimental precision, which is at least an order of magnitude cheaper than standard non-adaptive LES computations in the literature. Adaptive DNS/LES is a General Galerkin G2 method for turbulent Flow, where a stabilized Galerkin finite element method is used to compute approximate solutions to the Navier-Stokes equations, with the mesh being adaptively refined until a stopping criterion is reached with respect to the error in a chosen output of interest, in this paper c D . Both the stopping criterion and the mesh refinement strategy are based on a posteriori error estimates, in the form of a space-time integral of residuals multiplied by derivatives of the solution of an associated dual problem, linearized at the approximate solution, and with data coupling to the output of interest. There is no filtering of the equations, and thus no Reynolds stresses are introduced that need modelling. The stabilization in the numerical method is acting as a simple turbulence model.
Youichi Yasuda - One of the best experts on this subject based on the ideXlab platform.
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HYDRODYNAMIC FORCE ON A VERTICAL PLATE IN Subcritical Flow
Doboku Gakkai Ronbunshuu B, 1999Co-Authors: Yasushi Yamanaka, Youichi Yasuda, Iwao OhtsuAbstract:The hydrodynamic force acting on a vertical thin-plate has been studied experimentally and numerically under conditions in which the Flow is Subcritical and the variation of water surface is very small. The pressure acting on the upstream and downstream faces of the plate has been characterized and an experimental formula for the drag force has been proposed. The pressure magnitude and distribution on the plate has been calculated numerically by using the two dimensional incompressible Navier-Stokes equation under simplified conditions. The hydraulic condition for predicting the pressure and the drag force on the plate has been shown, and the velocity field around the plate has been discussed.
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Drag Force on Vertical Plate in Subcritical Flow
PROCEEDINGS OF HYDRAULIC ENGINEERING, 1997Co-Authors: Iwao Ohtsu, Yasushi Yamanaka, Youichi YasudaAbstract:The Flow conditions passing over a vertical plate in the Subcritical Flow are classified under a wide range of experimental conditions. The pressure magnitude and distribution pattern on the plate is characterized by the formation of an eddy immediately upstream of the plate and the curvature of the stream line passingover the plate. The drag force on the plate is formulated, and the relationship between the upstream and downstream depths of the plate is obtained. This study is useful for designing a submerged weir and a ground sill.
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hydraulic jump in sloping channels
Journal of Hydraulic Engineering, 1991Co-Authors: Iwao Ohtsu, Youichi YasudaAbstract:The transition from supercritical to Subcritical Flow in sloping channels is systematically investigated under a wide range of slopes. The hydraulic conditions for the formation of Djump, where the...
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Transition from supercritical to Subcritical Flow at an abrupt drop
Journal of Hydraulic Research, 1991Co-Authors: Iwao Ohtsu, Youichi YasudaAbstract:This paper presents a systematic investigation on the transition from supercritical to Subcritical Flow at an abrupt drop. Over a wide range of experimental conditions various types of Flow have been classified and the concept of low and high drops defined. When the Flow on the step is supercritical, the direction of the main Flow passing over the step can be decided from the momentum equation. The reason why various Flow conditions are formed has been explained. The hydraulic conditions required to form various types of Flow and their length characteristics have been clarified.
Iwao Ohtsu - One of the best experts on this subject based on the ideXlab platform.
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HYDRODYNAMIC FORCE ON A VERTICAL PLATE IN Subcritical Flow
Doboku Gakkai Ronbunshuu B, 1999Co-Authors: Yasushi Yamanaka, Youichi Yasuda, Iwao OhtsuAbstract:The hydrodynamic force acting on a vertical thin-plate has been studied experimentally and numerically under conditions in which the Flow is Subcritical and the variation of water surface is very small. The pressure acting on the upstream and downstream faces of the plate has been characterized and an experimental formula for the drag force has been proposed. The pressure magnitude and distribution on the plate has been calculated numerically by using the two dimensional incompressible Navier-Stokes equation under simplified conditions. The hydraulic condition for predicting the pressure and the drag force on the plate has been shown, and the velocity field around the plate has been discussed.
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Drag Force on Vertical Plate in Subcritical Flow
PROCEEDINGS OF HYDRAULIC ENGINEERING, 1997Co-Authors: Iwao Ohtsu, Yasushi Yamanaka, Youichi YasudaAbstract:The Flow conditions passing over a vertical plate in the Subcritical Flow are classified under a wide range of experimental conditions. The pressure magnitude and distribution pattern on the plate is characterized by the formation of an eddy immediately upstream of the plate and the curvature of the stream line passingover the plate. The drag force on the plate is formulated, and the relationship between the upstream and downstream depths of the plate is obtained. This study is useful for designing a submerged weir and a ground sill.
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hydraulic jump in sloping channels
Journal of Hydraulic Engineering, 1991Co-Authors: Iwao Ohtsu, Youichi YasudaAbstract:The transition from supercritical to Subcritical Flow in sloping channels is systematically investigated under a wide range of slopes. The hydraulic conditions for the formation of Djump, where the...
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Transition from supercritical to Subcritical Flow at an abrupt drop
Journal of Hydraulic Research, 1991Co-Authors: Iwao Ohtsu, Youichi YasudaAbstract:This paper presents a systematic investigation on the transition from supercritical to Subcritical Flow at an abrupt drop. Over a wide range of experimental conditions various types of Flow have been classified and the concept of low and high drops defined. When the Flow on the step is supercritical, the direction of the main Flow passing over the step can be decided from the momentum equation. The reason why various Flow conditions are formed has been explained. The hydraulic conditions required to form various types of Flow and their length characteristics have been clarified.
