scholarly journals Experimental Analysis of Fully Developed Turbulent Flow in an Elliptical Duct by Laser-Doppler Anemometer.

1994 ◽  
Vol 60 (571) ◽  
pp. 842-848
Author(s):  
Hitoshi Sugiyama ◽  
Mitsunobu Akiyama ◽  
Yoshinori Yakuwa ◽  
Hideki Wakayama
Keyword(s):  
Turbulent Flow ◽  
Experimental Analysis ◽  
Laser Doppler Anemometer ◽  
Laser Doppler ◽  
Fully Developed Turbulent Flow

scholarly journals Experimental Analysis of Anisotropic Turbulent Flow in a Distorting Duct by a Laser-Doppler Anemometer.

1992 ◽  
Vol 58 (550) ◽  
pp. 1753-1760
Author(s):  
Hitoshi SUGIYAMA ◽  
Mitsunobu AKIYAMA ◽  
Nao NINOMIYA ◽  
Yoshinori YAKUWA ◽  
Masaru HIRATA
Keyword(s):  
Turbulent Flow ◽  
Experimental Analysis ◽  
Laser Doppler Anemometer ◽  
Laser Doppler

Use of laser doppler anemometer for the investigation of turbulent flow of polymer solutions

1975 ◽  
Vol 29 (6) ◽  
pp. 1474-1478 ◽  
Author(s):  
N. A. Pokryvailo ◽  
D. A. Prokopchuk ◽  
Z. P. Shul'man
Keyword(s):  
Turbulent Flow ◽  
Polymer Solutions ◽  
Laser Doppler Anemometer ◽  
Laser Doppler

Turbulent Flow over a Plane Normal Wall

1980 ◽  
Vol 22 (4) ◽  
pp. 207-211 ◽  
Author(s):  
S. M. Fraser ◽  
M. H. Siddig
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Air Flow ◽  
Flow Patterns ◽  
Laser Doppler Anemometer ◽  
Laser Doppler ◽  
Plane Normal ◽  
Normal Wall ◽  
Side Walls

A DISA two-colour back-scatter laser Doppler anemometer was used to take measurements of mean and fluctuating velocities of an air flow of 4.6 × 104 Reynolds number in a short duct with a normal wall fixed to one side. Walls of 30 and 20 mm height were investigated and the resulting flow patterns were compared.

Some Experimental Results on Laser Doppler Velocimetry (LDV) and Birefringence (FIB) Studies of Non-Newtonian Fluids Flow Through Rectangular Channels

2003 ◽  
Author(s):  
Bernhard Gampert ◽  
Thomas Braemer ◽  
Thomas Eich ◽  
Torsten Dietmann
Keyword(s):  
Turbulent Flow ◽  
Laser Doppler Velocimetry ◽  
Xanthan Gum ◽  
Polymer Solutions ◽  
Laser Doppler ◽  
Doppler Velocimetry ◽  
Flow Properties ◽  
Square Channel ◽  
Rectangular Channels ◽  
Fully Developed Turbulent Flow

In the present study, the turbulence behaviour of polymer solutions is investigated using laser-Doppler velocimetry (LDV). At the same time, an attempt is made to determine a possibly occurring extension and orientation of the macromolecules by flow-induced birefringence (FIB). Flow-dynamic and rheo-optical experiments are presented which were performed in a smooth square channel in the area of the fully developed turbulent flow. The turbulent flow properties of aqueous solutions of PAAM and Xanthan Gum were studied. The Reynolds number was 30000. The concentration of the polymer solutions was varied between 300 wppm and 800 wppm for PR2300 and between 30 wppm and 120 wppm in the case of Xanthan Gum. The obtained experimental data indicate a significant dependence of the turbulent flow properties on the molecular structure of the polymers used. Furthermore, the extension and orientation of the macromolecules on the turbulent flow properties was investigated.

Effect of Vessel Tapering on the Transition to Turbulent Flow: Implications in the Cardiovascular System

1981 ◽  
Vol 103 (2) ◽  
pp. 116-120 ◽  
Author(s):  
F. J. Walburn ◽  
P. D. Stein
Keyword(s):  
Reynolds Number ◽  
Laminar Flow ◽  
Turbulent Flow ◽  
Cardiovascular System ◽  
Abdominal Aorta ◽  
Normal Subjects ◽  
Laser Doppler Anemometer ◽  
Laser Doppler

The purpose of this study is to explore the effect of tapering upon the tendency of flow to become turbulent in straight symmetric tubes. Velocity was measured with a laser Doppler anemometer in plexiglass tubes which tapered 0.5 deg, 1.5 deg, and 2.5 deg measured from the centerline to the wall. These angles were comparable to the angles of tapering observed in the abdominal aorta of normal subjects, 1.5 deg ± 0.2 deg (mean ± SEM) (range 0 deg to 3 deg). The transition Reynolds number (based on the diameter of the tube at the piont of measurement) increased as the angle of tapering increased. When the angle of tapering was constant, the transition Reynolds number increased with increasing distance into the tapered section. These observations suggest that tapering of the abdominal aorta tends to promote laminar flow.

Turbulent flow in a rectangular duct

1976 ◽  
Vol 78 (2) ◽  
pp. 289-315 ◽  
Author(s):  
A. Melling ◽  
J. H. Whitelaw
Keyword(s):  
Turbulent Flow ◽  
Turbulence Models ◽  
Laser Doppler Anemometer ◽  
Laser Doppler ◽  
Rectangular Duct ◽  
Reynolds Stresses ◽  
Mean Velocity ◽  
Fully Developed Flow ◽  
Developing Flow ◽  
Better Than

A detailed experimental study of developing turbulent flow in a rectangular duct was made using a laser-Doppler anemometer. The purposes of the work were to obtain data of value to fluid mechanicists, particularly those interested in the development and testing of mathematical turbulence models, and to evaluate the performance of the anemometer. For the first purpose, contours of axial mean velocity and turbulence intensity were measured in the developing flow, and all three mean velocity components and five of the six Reynolds stresses were obtained in the nearly fully developed flow.The symmetry of the present flow appears to be better than that of previous measurements and the range of measurements is more extensive. In addition, the laser-Doppler anemometer has the potential advantage, particularly in the measurement of secondary velocities, of avoiding probe interference.

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