Chemical Modified Fiber Fabry–Pérot Interferometer by Silver Mirror Reaction for Hot-Wire Anemometry

Abstract In this study, the easy-to-operate silver mirror reaction (SMR) was used for metallizing chromatography paper. The SMR-metallized paper was characterized by water contact angle measurements, a surface profiler, X-ray photoelectron spectroscopy, UV-vis spectroscopy, X-ray diffraction, and electrical resistance measurement. The characterization results show that Ag was successfully synthesized on cellulose fibers and was electrically conductive after cyclic bending. Moreover, this SMR-metallized paper was used as electrodes for fabricating a supercapacitor. This SMR-metallized paper could be used for realizing cost-effective flexible electronics applied in on-site biochemical sensing in resource-limited settings.

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Flow-Induced Vibration in a Single Row of Cylinders With p/D = 1.26

10.1115/pvp2021-62989 ◽

2021 ◽

Author(s):

Roberta F. Neumeister ◽

Adriane P. Petry ◽

Sergio V. Möller

Keyword(s):

Hot Wire ◽

Flow Induced Vibration ◽

Single Row ◽

Reference Flow ◽

Wake Interaction ◽

Hot Wire Anemometry ◽

Tube Banks ◽

Comparison Of The Results ◽

The Impact ◽

Space Ratio

Abstract Crossflow over a row of cylinders with a close space ratio presents an asymmetric configuration with large and narrow wakes behind the cylinders. The wake interaction can impact the vibration response of the cylinders. In tube banks, the impact results in damages to the equipment. The present experimental study aims to analyze the influence of close space observed in a single row of cylinders on the flow-induced vibration. The study compares a single row with fixed cylinders and a single row with one cylinder free to vibrate. The cylinder free to vibrate is tested in four configurations. The study was conducted with an aerodynamic channel with a cross-section of 0.193 × 0.146 m and smooth cylinders with a diameter of 25.1 mm, space ratio is 1.26. The measurements are executed with hot-wire anemometry and accelerometers, for the cases with one cylinder free to vibrate and with hot-wire anemometry and microphones for the case with all fixed cylinders. The Reynolds number ranges between 1.0 × 104 and 4.5 × 104, obtained with the reference flow velocity, measured with a Pitot tube, and the cylinder diameter. The comparison between the wake response for single row fixed and single row and free to vibrate are executed using Fourier transform and Wavelet Transform. The comparison of the results with the models presented in the literature to predict the elastic instability of the fluid in a single row of cylinders is performed.

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Combined Simultaneous Flow Visualization/Hot-Wire Anemometry for the Study of Turbulent Flows

Journal of Fluids Engineering ◽

10.1115/1.3240641 ◽

1980 ◽

Vol 102 (2) ◽

pp. 174-182 ◽

Cited By ~ 16

Author(s):

R. E. Falco

Keyword(s):

Pressure Gradient ◽

Flow Visualization ◽

Turbulent Flows ◽

Unsteady Flows ◽

Gradient Flows ◽

Hot Wire ◽

Visual Patterns ◽

Favorable Pressure Gradient ◽

Hot Wire Anemometry ◽

Scattering Light

The measurement of coherent motions in turbulent and unsteady flows is discussed. A technique which discriminates these motions based upon the patterns they create by scattering light from a fog of tiny oil drops is described. It is shown that hot-wire anemometry can be used in this oil fog so that hot-wire data can be conditionally sampled to the visual patterns, giving directly interpretable measures of the importance of the selected features. The three-dimensionality of the coherent motions can also be directly accounted for, using mutually orthogonal sheets of light. Results of step flows, and zero and favorable pressure gradient flows are described.

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