For efficient use of water, accurate measurement of flow in (field/laboratory) channels is required for many water resource projects. The present work is aimed to study the flow characteristics of a twin plate weir (two sharp-crested plates are placed one behind the other at some distance) under free and submerged flow conditions. Experiments are performed with four spacing of the twin plate we...

In this study, Gene expression programming (GEP) is employed as a new method for estimating the side weir discharge coefficient. The accuracy of existing equations in evaluating the side weir discharge coefficient is first examined. Afterward, taking into consideration the dimensionless parameters that affect the estimation of this parameter and sensitivity analysis, five different models are p...

Measurement of discharge in open channels is one of the main concerns in hydraulic engineering. The structures used for this aim should be accurate, economical and easy to use. Weirs are among the oldest and most convenient hydraulic structures that have been used in both laboratory and field for flow measurement in open channels. Due to limitations of simple sharp crested weirs, recently compo...

Long crested weirs are gaining popularity amongst the hydraulic engineers owing to obvious hydraulic advantage of flow magnification. These weirs can pass much higher floods from the available width of a natural water course. Such weirs may also be introduced in water treatment plants for mixing of chemicals. This paper discusses the advantages of long crested weirs, such as duckbill and labyri...

Basic experiments were conducted on a large-size broad-crested weir with an upstream rounded corner. Detailed velocity and pressure measurements were performed for a range of flow conditions. The results showed the rapid flow re-distribution at the upstream end of the weir, as well as next to the weir brink at large flow rates. Assuming non-uniform velocity and nonhydrostatic pressure distribut...

circular- crested weirs are employed for flow measurement among their other wide applications in hydraulic engineering. they can also be used to control water level in farm ponds and reservoirs. advantages of the circular crested weirs as compared to other weirs include the stable overflow pattern, the simplicity of design and their associated lower costs. in this study, the curvilinear flow pa...

Truncated sharp crested weirs are used to measure flow rate and control upstream water surface in irrigation canals and laboratory flumes. The main advantages of such weirs are ease of construction and capability of measuring a wide range of flows with sufficient accuracy. Artificial neural networks (ANNs) and genetic programming (GP) have recently been used for estimation of hydraulic data. In...

Laboratory experiments were carried out to investigate the hydraulic characteristics of full-cycle cosine and rectangular sharp-crested weirs in free flow condition. The head–discharge relationships determined theoretically discharge coefficients correlated with weir geometry for both rigid erodible bed conditions. proposed model showed higher comparison weirs. three-dimensional velocity profil...