IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 35th IAHR Congress - Chengdu (2013) : THEME 5 - FLUVIAL HYDRAULICS AND RIVER MANAGEMENT : Measurements of Bottom Velocities and Shear Stresses Through Ferrofluids
Measurements of Bottom Velocities and Shear Stresses Through Ferrofluids
Author : Rosaria Ester Musumeci, Vincenzo Marletta, Carla Faraci, Bruno AndĽ, Salvatore Baglio and Enrico Foti
A novel direct measurement strategy of bottom velocities and shear stresses based on the use of ferrofluids is presented. The proposed methodology is aimed at overcoming some of the limits of state-of-the-art instruments, for use in both turbulent conditions and in the presence of sediments. A preliminary experimental campaign has been carried out in steady conditions to test the effects of ferrofluid quantity and controlling permanent magnetic force as a function of the fluid velocities. An alternating current (AC) and a direct current (DC) conditioning circuits have been tested. The results have shown that there is a low sensitivity operating condition, when the ferrofluid is fully within the viscous sublayer. For velocities larger than 10 cm\s, the velocity-output voltage calibration curve has a monotone parabolic shape, which clearly proves a relationship between ferrofluid deformation and the bottom shear stresses. The sensitivity of the instrument is increased by a factor of 30 when the DC circuit is used.
File Size : 308,103 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 35th IAHR Congress - Chengdu (2013)
Date Published : 18/07/2016
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