Response Compensation Scheme for Constant-Current Hot-Wire Anemometry Based on Frequency Response Analysis

2011 ◽  
Author(s):  
Kazuhide Kaifuku ◽  
Soe Minn Khine ◽  
Tomoya Houra ◽  
Masato Tagawa
Keyword(s):  
Turbulent Flows ◽  
Constant Temperature ◽  
Response Speed ◽  
Wake Flow ◽  
Constant Current ◽  
Response Analysis ◽  
Compensation Scheme ◽  
Hot Wire ◽  
Velocity Fluctuations ◽  
Hot Wire Anemometry

Hot-wire anemometry (HWA) is used for measuring velocity fluctuations such as turbulent flows. It is generally operated in three modes; constant-temperature (CT), constant-current (CC) and constant-voltage (CV) types. The constant-temperature anemometer (CTA) is the mainstream anemometer, while others are rarely used in measuring normal turbulent flows because of their insufficient response speed. However, since the constant-current anemometer (CCA) can be composed of simple circuits, the HWA can be realized at quite a low cost. In this study, the response characteristics of the CCA are theoretically analyzed, and a compensation scheme is proposed. The scheme is experimentally tested in a turbulent wake flow formed behind a cylinder. As a result, it has been confirmed that the root-mean-square (rms) velocities and the power-spectrum distributions compensated by the present scheme agree well with those measured with CTA. Hence, the CCA provides reliable measurement of turbulent velocity fluctuations.

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

1980 ◽  
Vol 102 (2) ◽  
pp. 174-182 ◽  
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.

scholarly journals Simplified Calibration Method for Constant-Temperature Hot-Wire Anemometry

2020 ◽  
Vol 10 (24) ◽  
pp. 9058
Author(s):  
Hidemi Takahashi ◽  
Mitsuru Kurita ◽  
Hidetoshi Iijima ◽  
Seigo Koga
Keyword(s):  
Boundary Layer ◽  
Flow Velocity ◽  
Constant Temperature ◽  
Calibration Method ◽  
Large Temperature ◽  
Velocity Data ◽  
Hot Wire ◽  
Temperature Variations ◽  
Wire Temperature ◽  
Hot Wire Anemometry

This study proposes a unique approach to convert a voltage signal obtained from a hot-wire anemometry to flow velocity data by making a slight modification to existing temperature-correction methods. The approach was a simplified calibration method for the constant-temperature mode of hot-wire anemometry without knowing exact wire temperature. The necessary data are the freestream temperature and a set of known velocity data which gives reference velocities in addition to the hot-wire signal. The proposed method was applied to various boundary layer velocity profiles with large temperature variations while the wire temperature was unknown. The target flow velocity was ranged between 20 and 80 m/s. By using a best-fit approach between the velocities in the boundary layer obtained by hot-wire anemometry and by the pitot-tube measurement, which provides reference data, the unknown wire temperature was sought. Results showed that the proposed simplified calibration approach was applicable to a velocity range between 20 and 80 m/s and with temperature variations up to 15 °C with an uncertainty level of 2.6% at most for the current datasets.

Hot wire anemometry for the measurement of temperature and velocity fluctuations inside a thermoacoustic cooler

2006 ◽  
Vol 119 (5) ◽  
pp. 3415-3415 ◽  
Author(s):  
Arganthaël Berson ◽  
Philippe Blanc‐Benon ◽  
Luc Mongeau ◽  
Insu Paek
Keyword(s):  
Hot Wire ◽  
Velocity Fluctuations ◽  
Hot Wire Anemometry ◽  
Thermoacoustic Cooler

scholarly journals Assessment of uncertainties in hot-wire anemometry and oil-film interferometry measurements for wall-bounded turbulent flows

2018 ◽  
Vol 72 ◽  
pp. 57-73 ◽  
Author(s):  
Saleh Rezaeiravesh ◽  
Ricardo Vinuesa ◽  
Mattias Liefvendahl ◽  
Philipp Schlatter
Keyword(s):  
Turbulent Flows ◽  
Hot Wire ◽  
Oil Film ◽  
Hot Wire Anemometry

Modelling and operation of sub-miniature constant temperature hot-wire anemometry

2016 ◽  
Vol 27 (12) ◽  
pp. 125301 ◽  
Author(s):  
M Samie ◽  
J H Watmuff ◽  
T Van Buren ◽  
N Hutchins ◽  
I Marusic ◽  
...  
Keyword(s):  
Constant Temperature ◽  
Hot Wire ◽  
Hot Wire Anemometry

scholarly journals Constant-Temperature Anemometer Bandwidth Shape Determination for Energy Spectrum Study of Turbulent Flows

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4495
Author(s):  
Paweł Ligęza
Keyword(s):  
Energy Spectrum ◽  
Turbulent Flows ◽  
Constant Temperature ◽  
Indirect Method ◽  
Natural Phenomena ◽  
Hot Wire ◽  
Common Occurrence ◽  
Wide Range ◽  
Shape Determination ◽  
Constant Temperature Anemometer

Due to their common occurrence and fundamental role in human-realized processes and natural phenomena, turbulent flows are subject to constant research. One of the research tools used in these studies are hot-wire anemometers. These instruments allow for measurements in turbulent flows in a wide range of both velocities and frequencies of fluctuations. This article describes a new indirect method of determining the bandwidth shape of a constant-temperature anemometer. The knowledge of this bandwidth is an important factor in the study of the energy spectrum of turbulent flows.

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