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
1975 ◽  
Vol 29 (6) ◽  
pp. 1474-1478 ◽  
Author(s):  
N. A. Pokryvailo ◽  
D. A. Prokopchuk ◽  
Z. P. Shul'man

1980 ◽  
Vol 22 (4) ◽  
pp. 207-211 ◽  
Author(s):  
S. M. Fraser ◽  
M. H. Siddig

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.


1981 ◽  
Vol 103 (2) ◽  
pp. 116-120 ◽  
Author(s):  
F. J. Walburn ◽  
P. D. Stein

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.


1976 ◽  
Vol 78 (2) ◽  
pp. 289-315 ◽  
Author(s):  
A. Melling ◽  
J. H. Whitelaw

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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