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Side weirs are flow diversion devices commonly used in irrigation, land drainage and urban sewage systems. It is essential for hydraulic and environmental engineers involved in the design of side weirs to predict the discharge coefficient correctly. The aim of this study is to present an accurate equation for discharge coefficients along the bend of sharp-crested rectangular side weirs based on a total of 1504 experimental runs. The discharge coefficient of the rectangular side weir along the bend depends on the dimensionless parameters of Froude number in the main channel , the angle of bend curvature , the ratio of weir length to main channel width /, the ratio of weir length to radius of main channel centreline / and the ratio of weir height to upstream flow depth / . In particular, the variables / and / are not seen in any equation for a rectangular side weir located on a curved channel. However, it was found that these dimensionless parameters were significantly important for the overflow rate. Moreover, the equation in the literature needs interpolation in order to obtain the discharge coefficient for different / and values. Therefore, a reliable equation containing all dimensionless parameters for calculating the discharge coefficient was introduced. [ABSTRACT FROM AUTHOR]

Baffled chutes are commonly used in storm water systems, irrigation systems, canal wasteway systems, river training, and drops for energy dissipation. There is a close relationship between energy dissipation and oxygen transfer efficiency. Oxygen transfer across the air-water interface at a hydraulic structure occurs through self-aeration along the chute, and by flow aeration in the hydraulic jump at the downstream end of the structure. The oxygen concentration in surface water is a primary indicator of the water quality for human use and for the aquatic biota. This present study focused on predicting the aeration efficiency of baffled chutes. The variation of the aeration efficiency for stepped, wedge, trapezoidal and T-shaped baffle blocks was investigated in relation to chute angle, unit discharge, and chute height. The results obtained from this approach show that baffled chutes are effective for oxygen transfer. Thus, an empirical correlation predicting aeration efficiency was developed. This new equation has practical implications for predicting baffled chute aeration efficiency. [ABSTRACT FROM AUTHOR]