Discharge coefficient for an inclined side weir crest using a constant energy approach

Mohammed, Mwafaq Y.; Mohammed, Ahmed Y.

doi:10.1016/j.flowmeasinst.2011.06.008

Cited by 13 publications

(6 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, Table 2 (C M , 7-5 networks) also shows an increase in the variability of the results, highlighted by larger values of the standard deviation of R 2 , when channel slope is not included among the input parameters. Despite this result, it is interesting to note that almost all experimental studies in the literature on the assessment of the discharge coefficient for side weirs usually neglect these parameters, relying only on the global energy constancy check, as in [15,16] (upstream vs. downstream sections of the side weir).…”

Section: Neurons (I II Layer)mentioning

confidence: 99%

“…Equations (15) and (16) are other expressions used in some studies under the misleading definition of "De Marchi's formula" (e.g., [13,[15][16][17][18]), for calculating the diverted flow and, consequently, the discharge coefficient in side weirs:…”

Section: Introduction: Theoretical Background and Aims Of The Researchmentioning

confidence: 99%

“…Water 2019, 11, 2585 4 of 14 In this last approach, a key role is played by the method chosen to evaluate the water depth, y, indicated in Equation (15). Still, in many studies this is not often explicitly stated: the most common solution, where indicated, is to consider it equal to the water depth in the upstream section of the weir, y 1 [13,17,18].…”

Section: Introduction: Theoretical Background and Aims Of The Researchmentioning

confidence: 99%

“…This preliminary excursus on the theoretical background has been motivated by a thorough review of the literature on side weirs. Indeed, the analysis highlighted that, while in the past century attention was precisely addressed to the definition of the discharge coefficient under De Marchi's theory, C M (e.g., [2,3,5,6]), recent years have experienced an increase in the number of works that have aimed to evaluate the discharge coefficient without clearly defining measured input variables, not reporting used equations for the determination of the coefficient or even incorrectly applying the different approaches (e.g., [13,[15][16][17][18]), as also noted by Vatankhah et al [19]. This confusion may generate misinterpretation of the results or incorrect use of existing experimental data in the literature, given that discharge coefficients evaluated using different discharge equations, with a different physical basis, are not comparable [19].…”

Section: Introduction: Theoretical Background and Aims Of The Researchmentioning

confidence: 99%

See 3 more Smart Citations

Are We Correctly Using Discharge Coefficients for Side Weirs? Insights from a Numerical Investigation

Bacco

Scorzini

2019

Water

View full text Add to dashboard Cite

A key issue in the design of side weirs is the experimental assessment of the discharge coefficient. This can be determined by laboratory measurements of discharge and water depths at the up-and downstream ends of the weir by using De Marchi's approach, consisting in the solution of the 1D dynamic equation of spatially varied steady flow with non-uniform discharge, under the assumption of energy conservation. This study originates from a recent alarming proliferation of works that evaluate the discharge coefficient for side weirs without clearly explaining the experimental methodology and/or even incorrectly applying modelling approaches, thus generating possible misinterpretations of the results. In this context, the present paper aims to highlight the effects of using oversimplified and/or heterogenous models (relying on different assumptions) for the experimental determination of the discharge coefficient for side weirs. Furthermore, a sensitivity analysis is performed to detect the most influencing hydraulic and geometric parameters on each considered model. The overall results clearly indicate the wrongness of using or building not homogeneous discharge coefficient datasets to obtain and/or compare predictive experimental discharge coefficient formulas. We finally show how neural networks could provide a possible solution to these heterogeneity issues.

show abstract

Section: Neurons (I II Layer)mentioning

confidence: 99%

Section: Introduction: Theoretical Background and Aims Of The Researchmentioning

confidence: 99%

Section: Introduction: Theoretical Background and Aims Of The Researchmentioning

confidence: 99%

Section: Introduction: Theoretical Background and Aims Of The Researchmentioning

confidence: 99%

See 2 more Smart Citations

Are We Correctly Using Discharge Coefficients for Side Weirs? Insights from a Numerical Investigation

Bacco

Scorzini

2019

Water

View full text Add to dashboard Cite

show abstract

“…Many experimental studies were conducted on the discharge capacity side weirs in a straight channel. Side weir in subcritical flow was investigated in the rectangular straight channels by many researchers (Ramamurthy et al 1995;Borghei et al 1999;Huagao et al 2007;Mohammed and Mohammed 2011;Vatankhah 2012). In addition, many experimental investigations have been conducted on the labyrinth weir in the straight channels.…”

Section: Introductionmentioning

confidence: 99%

Experimental study and performance comparison on various types of rectangular piano key side weirs at a 120° section of a 180° curved channel

2020

View full text Add to dashboard Cite

Application of side weirs with high effective length is necessary to discharge excessive flows, to control the flow in water conveyance systems, and irrigation and drainage systems. Most of the studies on the side weirs have been conducted on the straight channels and linear weirs. The flow pattern on the outer arc of the curved channels and its suitability for side weir can be used and combined with the piano key weirs. So far, no comparison has been made on rectangular piano key side weirs (RPKSW) at a 120° Section of a 180° Curved Channel. In this study, an experimental study was performed on A-, B-, C-, and D-type RPKSW at a bend angle of 120 degrees. The results showed that the specific energy at two ends of the RPKSWs was the same, with a slight difference of 3.4% for A-Type, 1.3% for B-Type, 1.1% for C-Type, and 1.8% for D-Type weirs. The discharge coefficients of the studied weirs were also investigated, and it was concluded that B-Type weir has better performance than other weirs. On average, the discharge coefficient of B-Type weir was 9.9%, 21.2%, and 24.1% higher than that of A-Type, C-Type, and D-Type weir, respectively. It was shown that the ratio of P/h1 is the main parameter affecting the weir discharge coefficient. Finally, an empirical equation was proposed for each weir. The proposed equation has MAE = 0.028 for A-Type weir, MAE = 0.041 for B-Type weir, MAE = 0.049 for C-Type weir, and MAE = 0.053 for D-Type weir.

show abstract

Numerical study of the effect of length change on the flow pattern around a side weir in a converging channel

Ghorbannia

Eghbalzadeh

2018

Acta Mech

View full text Add to dashboard Cite

Discharge coefficient for an inclined side weir crest using a constant energy approach

Cited by 13 publications

References 12 publications

Are We Correctly Using Discharge Coefficients for Side Weirs? Insights from a Numerical Investigation

Are We Correctly Using Discharge Coefficients for Side Weirs? Insights from a Numerical Investigation

Experimental study and performance comparison on various types of rectangular piano key side weirs at a 120° section of a 180° curved channel

Numerical study of the effect of length change on the flow pattern around a side weir in a converging channel

Contact Info

Product

Resources

About