Accuracy of a laser doppler velocimeter for instantaneous velocity measurements on rotating solid surfaces

1990 ◽  
Author(s):  
Milind M. Rajadhyaksha ◽  
Warren H. Stevenson
Keyword(s):  
Instantaneous Velocity ◽  
Laser Doppler ◽  
Solid Surfaces ◽  
Laser Doppler Velocimeter ◽  
Velocity Measurements

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.

Blood velocity measurements using a fiber-coupled self-mixing diode-laser Doppler velocimeter

1993 ◽  
Author(s):  
Frits F. M. de Mul ◽  
Marco H. Koelink ◽  
Ralph Berendsen ◽  
Jan Greve ◽  
Reindert Graaff ◽  
...  
Keyword(s):  
Diode Laser ◽  
Blood Velocity ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Velocity Measurements

Gas Velocity Measurements Within a Compressor Rotor Passage Using the Laser Doppler Velocimeter

1973 ◽  
Vol 95 (2) ◽  
pp. 91-96 ◽  
Author(s):  
D. C. Wisler ◽  
P. W. Mossey
Keyword(s):  
High Speed ◽  
Axial Compressor ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Seed Particle ◽  
Gas Velocity ◽  
Velocity Measurements ◽  
Flow Measurements ◽  
Velocity Magnitude ◽  
New Instrument

The laser Doppler velocimeter, a new instrument capable of making nondisturbing gas velocity measurements, was used to investigate the flowfield within the rotating blade row of a low speed axial compressor. The velocimeter operates by measuring the transit time of a seed particle across interference fringes produced at the intersection of a split and crossed laser beam. The velocity (magnitude and direction) measurements made with the laser at the rotor inlet and discharge generally agreed within 2 to 3 per cent with measurements made with a hot film anemometer, pitot-static probe and wedge and tuft angle probes. Detailed flowfield measurements within the rotor passage were then obtained and compared with the analytical results from a potential flow model. This technique shows promise in making detailed flow measurements within high speed fans, compressors, turbines and nozzles, including the mapping of shock structures.

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