منابع مشابه
Hot-wire anemometry for superfluid turbulent coflows.
We report the first evidence of an enhancement of the heat transfer from a heated wire to an external turbulent coflow of superfluid helium. We used a standard Pt-Rh hot-wire anemometer and overheat it up to 21 K in a pressurized liquid helium turbulent round jet at temperatures between 1.9 K and 2.12 K. The null-velocity response of the sensor can be satisfactorily modeled by the counterflow m...
متن کاملSpatial resolution correction for hot-wire anemometry in wall turbulence
We investigate spatial resolution issues in hot-wire anemometry measurements of turbulence intensity and energy spectra. Single normal hot-wire measurements are simulated by means of filtering direct numerical simulation (DNS) of turbulent channel flow at Res 1⁄4 934. Through analysis of the two-dimensional energy spectra from the DNS, the attenuation of the small-scale energy levels is documen...
متن کاملHighly Sensitive Hot-Wire Anemometry Based on Macro-Sized Double-Walled Carbon Nanotube Strands
This paper presents a highly sensitive flow-rate sensor with carbon nanotubes (CNTs) as sensing elements. The sensor uses micro-size centimeters long double-walled CNT (DWCNT) strands as hot-wires to sense fluid velocity. In the theoretical analysis, the sensitivity of the sensor is demonstrated to be positively related to the ratio of its surface. We assemble the flow sensor by suspending the ...
متن کاملA calibration technique to correct sensor drift issues in hot-wire anemometry
Accurate calibration is imperative to obtain reliable flow measurements using hot-wire anemometry. Calibration errors owing to temperature drift, wire degradation, changes in ambient conditions etc can lead to substantial uncertainties in hot-wire measurements. A new calibration procedure is implemented here to account for most forms of drift that are typically encountered during high quality f...
متن کاملA new criterion for end-conduction effects in hot-wire anemometry
The effect of end conduction on constant temperature hot-wire anemometry was studied. A new parameter, = ( /d)√4a(kf /k)Nu, is proposed to describe the significance of end conduction more comprehensively than the commonly used length-to-diameter ratio /d, in that it allows for material property variations, resistance ratio and Reynolds number effects. Numerical and experimental data are used to...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1919
ISSN: 0036-8733
DOI: 10.1038/scientificamerican02151919-106supp