A Low-Cost Inertial Sensor Based on Shaped Magnetic Fluids

Journal of Hydraulic Research

Sánchez‐Arcilla

et al. 2018

The measurement of the near-bottom flow characteristics is crucial to correctly understand coastal processes. Aiming at overcoming some of the limits of present state-of-the-art measuring instruments, we propose a novel approach to measure bottom shear stress under currents and waves based on the exploitation of magneto-rheological fluids, named ferrofluids. In particular the deformation of a magnetically controlled ferrofluid drop O(0.01 ml) is transduced by a conditioning circuit into an output voltage which is proportional to the bottom shear stress. Calibration curves are presented for both steady-current and regular wave conditions, over fixed and weakly mobile beds, by showing that the behaviour of the proposed measuring system can be assumed linear. In the range of the investigated parameters, it is shown that the working range is comprised between 0.08 N/m 2 and an upper limit which is a function of the controlling magnetic field and of the flow type.

Section: Ferrofluid-based Measurement Methodologymentioning

confidence: 99%

A ferrofluid-based sensor to measure bottom shear stresses under currents and waves

Musumeci

Journal of Hydraulic Research

Sánchez‐Arcilla

et al. 2018

“…Ferrofluids allows applications in several contexts: sealing for several industrial processes, loudspeakers, inertial dampers, angular position sensors, and computer disk drives are examples of applications where these materials have been widely adopted. An advantage in using magnetic fluids arises from the possibility to implement efficient, reliable, and robust against mechanical shocks sensors and actuators [35]- [46] thanks to the absence of mechanical moving parts and of solidinertial masses and to the intrinsic feature to be shapeless. Another advantage of ferrofluid based sensors is the electrical insulation between the readout electronics and the liquid medium.…”

Section: Proposed Methodology To Measure Wave Near-bed Velocity Amentioning

confidence: 99%

“…Another advantage of ferrofluid based sensors is the electrical insulation between the readout electronics and the liquid medium. This gives the possibility to easily control fluids and to implement measurements in liquids [29], [41]- [46].…”

Section: Proposed Methodology To Measure Wave Near-bed Velocity Amentioning

confidence: 99%

Measurement of Wave Near-Bed Velocity and Bottom Shear Stress by Ferrofluids

Musumeci

IEEE Trans. Instrum. Meas.

Andò

et al. 2015

Self Cite

A novel direct measurement strategy of wave near-bed velocity and bottom shear stress 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 presence of both surface waves and sediments. An inductive readout strategy is proposed to sense displacements of the ferrofluid spike over the inductive circuit due to the flow. Experimental tests have been performed in a wave tank both in hydrostatic conditions and in the presence of regular linear waves corresponding to deep and intermediate water depth cases. Obtained results indicate the applicability of the proposed strategy also in the presence of suspended load (either moderate or intense) and of a moderate bed load transport.Index Terms-Bed velocity, bottom shear stress, ferrofluid, inductive readout, sediments, waves. 0018-9456

“…In recent years authors have proposed many novel sensing solutions based on ferrofluids [10][11][12][13][14].…”

Section: The Proposed Methodologymentioning

confidence: 99%

Measurement of bottom velocities and shear stresses by ferrofluids at the sea bottom

Andò

Baglio

2014 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) Proceedings

et al. 2014

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 presence of both surface waves and sediments. An inductive readout strategy is proposed along with experimental results which indicate the applicability of the proposed strategy.