scholarly journals Acoustic phase velocity measurements in a bubbly liquid using a fiber optic laser Doppler velocimeter

1992 ◽  
Vol 92 (4) ◽  
pp. 2454-2454
Author(s):  
Stanley A. Cheyne ◽  
Carl T. Stebbings ◽  
Ronald A. Roy
Keyword(s):  
Phase Velocity ◽  
Fiber Optic ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Bubbly Liquid ◽  
Velocity Measurements ◽  
Acoustic Phase

Integrated Microcomputer-LDV Instrumentation for Studying Finite Wing Aerodynamics

1993 ◽  
Author(s):  
Abdollah Khodadoust
Keyword(s):  
Reynolds Number ◽  
Flow Field ◽  
Data Acquisition ◽  
Fiber Optic ◽  
Three Dimensional ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Ice Accretion ◽  
Wing Model ◽  
Finite Wing

Abstract The effect of a simulated glaze ice accretion on the flow field of a three-dimensional wing is studied experimentally. A PC-based data acquisition and reduction system was used with a four-beam two-color fiber-optic laser Doppler velocimeter (LDV) to map the flow field along three spanwise cuts on the model. Results of the LDV measurements on the upper surface of the finite wing model without the simulated glaze ice accretion are presented for α = 0 degrees at Reynolds number of 1.5 million. Measurements on the centerline of the clean model compared favorably with theory.

A high-power fiber optic laser Doppler velocimeter

1984 ◽  
Vol 17 (11) ◽  
pp. 977-980 ◽  
Author(s):  
D A Jackson ◽  
J D C Jones ◽  
R K Y Chan
Keyword(s):  
High Power ◽  
Fiber Optic ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter

scholarly journals Laser-Doppler measurements on a round turbulent jet in dilute polymer solutions

1973 ◽  
Vol 60 (4) ◽  
pp. 721-731 ◽  
Author(s):  
Steven J. Barker
Keyword(s):  
Polymer Solutions ◽  
Initial Conditions ◽  
Laser Doppler ◽  
Turbulent Jet ◽  
Laser Doppler Velocimeter ◽  
Doppler Velocity ◽  
Velocity Measurements ◽  
Convergent Nozzle ◽  
Round Jets ◽  
Dilute Polymer Solutions

A laser-Doppler velocimeter suitable for the measurement of mean and fluctuating flow velocities in water is described. Results of a study using this system in an axisymmetric turbulent jet of water and dilute polymer solutions are given. The laser-Doppler technique is better suited for such measurements than either Pitot tubes or heat-transfer gauges because the Doppler velocity measurements are independent of the physical properties of the fluid. Previous velocity measurements in polymer jets have suffered from the effects of the additives upon the sensors.Turbulent round jets with Reynolds numbers between 5000 and 50000 were studied. For a jet issuing from a convergent nozzle the additives were found to have no effect upon the mean axial velocity or turbulence intensity at any point in the jet. However, for a jet issuing from a long length of circular pipe, the additives reduced the centre-line velocity and increased the turbulence level in the early part of the jet. Thus the principal effect of a polymer additive upon the jet appears to result from its effect upon the initial conditions.

Acoustic Phase Velocity Measurements along General Directions in Non-Isotropic Crystals. II. Layer Modes for Thin Films

1971 ◽  
Vol 49 (12) ◽  
pp. 1606-1610 ◽  
Author(s):  
S. L. McBride ◽  
G. W. Farnell
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Lithium Niobate ◽  
Phase Velocity ◽  
Test Specimen ◽  
Gold Films ◽  
Velocity Measurements ◽  
Elastic Surface ◽  
Film Substrate ◽  
Acoustic Phase

The usefulness of the immersion–reflection technique for the measurement of the angular dependence of the dispersion curves for elastic surface waves in anisotropic thin-film, substrate combinations is demonstrated. The example chosen consists of gold films on a substrate of Y-cut lithium niobate, the latter being both highly anisotropic and piezoelectric. The velocity accuracy of the measurements is about ±0.3% and the frequency of operation is limited by the attenuation in the liquid medium in which the test specimen is immersed.

Acoustic phase velocity measurements with nanometer resolution by scanning acoustic force microscopy

1998 ◽  
Vol 66 (7) ◽  
pp. S223-S226 ◽  
Author(s):  
E. Chilla ◽  
T. Hesjedal ◽  
H.-J. Fröhlich
Keyword(s):  
Phase Velocity ◽  
Velocity Measurements ◽  
Nanometer Resolution ◽  
Force Microscopy ◽  
Acoustic Phase
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