Investigation of the development of laminar flow at the entrance of a two-dimensional channel, using a laser-doppler velocimeter

1976 ◽  
Vol 10 (5) ◽  
pp. 850-853 ◽  
Author(s):  
V. P. Ivanov ◽  
V. P. Klochkov ◽  
L. F. Kozlov ◽  
V. I. Orlanov
Keyword(s):  
Laminar Flow ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Two Dimensional

Two-dimensional point laser Doppler velocimeter for velocity measurement

2014 ◽  
Vol 22 (10) ◽  
pp. 2627-2632
Author(s):  
李秀明 LI Xiu-ming ◽  
黄战华 HUANG Zhan-hua ◽  
李翔宇 LI Xiang-yu ◽  
张昊 ZHANG Hao ◽  
龙宁波 LONG Ning-bo
Keyword(s):  
Velocity Measurement ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Two Dimensional

A study of laminar flow in low aspect ratio lid-driven cavities

2002 ◽  
Vol 29 (3) ◽  
pp. 436-447 ◽  
Author(s):  
Y Yang ◽  
A G Straatman ◽  
R J Martinuzzi ◽  
E K Yanful
Keyword(s):  
Reynolds Number ◽  
Laminar Flow ◽  
Aspect Ratio ◽  
Numerical Solutions ◽  
Cavity Flow ◽  
Momentum Equation ◽  
Laser Doppler Velocimeter ◽  
Countercurrent Flow ◽  
Two Dimensional ◽  
Low Aspect Ratio

The evolution to fully developed laminar flow in low aspect ratio, two-dimensional, lid-driven cavities has been studied experimentally and numerically. Velocity measurements were made in water in a moving-lid apparatus using a laser Doppler velocimeter (LDV). Numerical solutions for the cavity flow were obtained by solving the two-dimensional mass-momentum equation set in a finite-volume framework. The measured and predicted results were in excellent agreement. Fully developed cavity flow is said to exist when the main regions of the flow field become independent of the aspect ratio. When fully developed conditions prevail, a region of countercurrent flow (CCF) separates the end structures, which are decoupled. The extent of the end regions is shown to grow linearly with increasing Reynolds number Re, based on the lid speed and the cavity height. Consequently, the critical aspect ratio for the onset of fully developed flow is also linearly dependent on Re. Above a critical Reynolds number, Re [Formula: see text] 300, the flow becomes unsteady, and a lower-wall, tertiary vortex appears, which is thought to be associated with the onset of hydrodynamic instability.Key words: lid-driven cavity, laminar flow, shallow water cover, countercurrent flow.

Laminar Fluid Flow Measurements Employing a White Light Fringe Image Velocimeter (WFIV)

1979 ◽  
Vol 46 (1) ◽  
pp. 218-220 ◽  
Author(s):  
J. H. C. Chan ◽  
E. A. Ballik
Keyword(s):  
Fluid Flow ◽  
Laminar Flow ◽  
White Light ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Flow Measurements ◽  
Laminar Fluid Flow ◽  
Flow Velocities

A compact white light fringe image velocimeter (WFIV) is used to measure laminar flow. It is demonstrated, by comparison with similar measurements employing a differential laser Doppler velocimeter (DLDV), that the WFIV is a practical and important technique for determining flow velocities.

Two-Dimensional Periodic Natural Convection in a Rectangular Enclosure of Aspect Ratio One

1985 ◽  
Vol 107 (4) ◽  
pp. 850-854 ◽  
Author(s):  
D. G. Briggs ◽  
D. N. Jones
Keyword(s):  
Natural Convection ◽  
Laminar Flow ◽  
Aspect Ratio ◽  
Boundary Conditions ◽  
Lower Boundary ◽  
Laser Doppler Velocimeter ◽  
Two Dimensional ◽  
Velocity Fluctuations ◽  
Vertical Walls ◽  
Rayleigh Numbers

A two-dimensional rectangular cavity of aspect ratio one is studied experimentally using a laser-doppler velocimeter. The enclosure is air filled and consists of two vertical walls at unequal isothermal temperatures and two connecting horizontal walls with temperatures varying linearly between the two vertical surfaces. This study clearly defines the existence of periodic laminar flow regimes detectable at Ra numbers above 0.3 × 107. These periodic variations in velocity are induced by the upper and lower boundary conditions. The envelopes of vertical and horizontal velocity fluctuations are reported as a function of position for Rayleigh numbers of 0.25 × 107, 0.50 × 107, and 0.85 × 107. In addition, the effect of Ra number on frequency of flow is reported.

Calibration Method of Two-Dimensional Laser Doppler Velocimeter in Land Integrated Navigation System

2018 ◽  
Vol 45 (8) ◽  
pp. 0804004
Author(s):  
王琦 Wang Qi ◽  
高春峰 Gao Chunfeng ◽  
聂晓明 Nie Xiaoming ◽  
周健 Zhou Jian ◽  
魏国 Wei Guo ◽  
...  
Keyword(s):  
Navigation System ◽  
Calibration Method ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Two Dimensional ◽  
Integrated Navigation ◽  
Integrated Navigation System

Two-dimensional laser Doppler velocimeter using polarized beams and 90° phase shift for discrimination of velocity direction

Optik ◽  
2011 ◽  
Vol 122 (11) ◽  
pp. 974-977 ◽  
Author(s):  
Koichi Maru ◽  
Liu Yan Hu ◽  
Rong Sheng Lu ◽  
Yusaku Fujii ◽  
P.P. Yupapin
Keyword(s):  
Phase Shift ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Two Dimensional ◽  
Polarized Beams
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