DETERMINАTION OF THE BАNK COEFFICIENT АND EVАLUАTION OF ITS EFFECT ON VELOCITY DISTRIBUTION IN RECTАNGULАR CONCRETE-LINED CHАNNELS

Abstract

This article presents the results of a study on the determination of the bank coefficient and the evaluation of velocity distribution in rectangular concrete-lined channels. The experiments were conducted in the laboratory of “Smart Solution System” LLC on the specially constructed K-2 channel. Nine verticals were selected across the channel cross-section, and velocity measurements were taken at depths of 10 cm, 23 cm, and 33 cm from the water surface. To improve accuracy, each measurement was repeated three times, and the final values were calculated as arithmetic means. The measurements were carried out using a Universal Muline (CM-32) hydrometric current meter and an electromagnetic flowmeter. Based on the obtained data, a specific formula for determining the bank coefficient was developed. The calculations showed that the value of the bank coefficient was T=0.92. Furthermore, the discharge determined from hydrometric measurements was Q=0.443 m³/s, which was very close to the discharge obtained from the electromagnetic flowmeter — Q=0.445 m³/s. The difference was only ΔQ=0.002 m³/s, corresponding to an error of 1%. The results demonstrated that flow velocity decreases sharply in the bank zones, while higher values are observed in the central part of the channel. The maximum velocity difference between the banks and the channel center was found to be Δϑ=16–29%. These findings apply to rectangular concrete-lined channels with a width of 2.5 m, whereas channels of different shapes and dimensions require further investigation.