Determination of the magnitudes and signs of flow parameters by hot‐wire anemometry. Part II. Measurements using a triple hot‐wire probe

1989 ◽  
Vol 60 (7) ◽  
pp. 1281-1285
Author(s):  
Michael Acrivlellis
Keyword(s):  
Hot Wire ◽  
Wire Probe ◽  
Flow Parameters ◽  
Hot Wire Anemometry

Accurate Boundary Layer Measurements using Hot-Wire Anemometry - Improvements and Error Analysis

2021 ◽  
pp. 1-15
Author(s):  
Silvio Chemnitz ◽  
Reinhard Niehuis
Keyword(s):  
Boundary Layer ◽  
Heat Effect ◽  
Correction Term ◽  
Accurate Determination ◽  
Hot Wire ◽  
Static Correction ◽  
Transitional State ◽  
Sensor Position ◽  
Hot Wire Anemometry

Abstract In this paper two approaches are presented dealing with common challenges of 2D boundary layer measurements with hot-wire anemometry under challenging test conditions. Novel procedures for accurate determination of the sensor position and correction of the wall heat effect were developed and tested at high free stream velocities of about M1 = 0.3 and thin boundary layers (δ99 = 0.7 - 3.5 mm) of different transitional state in a low density environment. First of all, a novel procedure for automatized determination of the accurate hot-wire sensor position relative to the wall is presented. The quantification and correction of possible sub-miniature sensor misalignments is achieved by taking advantage of the linear nature of the laminar sub-layer of each boundary layer. The statistical approaches for identification and verification of the linear sub-layer demonstrate satisfying results of minimized position uncertainties of about 24 μm. Secondly, a highly adaptable method for correction of the well-known wall heat effect is presented. In contrary to a series of static correction approaches, the biased velocity information is corrected by optimizing the parameters of an exponential approach, where the correction term is optimized for each boundary layer individually. This novel approach resolves the problem of limited applicability of static correction methods, caused by system inherent measurement uncertainties.

HOT WIRE METHOD FOR DETERMINATION OF THE THERMAL CONDUCTIVITY OF SUGAR CANE FIBERS

2020 ◽  
Author(s):  
Marcelo Borges dos Santos ◽  
CLAUDIA BITTENCOURT ◽  
Ana Carolina Mendonça Mansur ◽  
Luís Mauro Moura ◽  
Carlos Augusto Castro Ferreira
Keyword(s):  
Thermal Conductivity ◽  
Sugar Cane ◽  
Hot Wire ◽  
Wire Method

Hot-wire Anemometry in Low-Density Flows

AIAA Journal ◽  
1971 ◽  
Vol 9 (10) ◽  
pp. 2019-2027 ◽  
Author(s):  
E. M. SCHMIDT ◽  
R. J. CRESCI
Keyword(s):  
Low Density ◽  
Hot Wire ◽  
Hot Wire Anemometry

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

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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