Torsional current - meter for channels

Abstract

The main objective of this paper is to present the results of the experimental investigation of a Zarea-type torsional velocity-meter. For this, a torsional meter was designed, built and tested in the laboratory. The current meter consists of an axial rotor with blades fixed to a shaft which is in turn fixed to a rigid hub. The force of the water flow produces a torque which deforms the shaft. The current meter has been statically calibrated, thereby establishing the variational curve of the torsion angle as a function of the applied torque. A laboratory facility has been constructed in which tests were run for water speeds of up 3m/s. The torque measurements were taken by using strain gauges. The methodology and the equipment used for the experimental evaluation are shown. Additionally illustrated are the calibration curves, the analysis of obtained results, some advantages and disadvantages, and the range of application of the torsional current-meter are all discussed.