A laser-Doppler technique for the measurement of particle velocity.

Babcock, Wayne R.; Seifert, Howard S.; James, Robert N.

doi:10.2514/3.4461

Cited by 21 publications

(3 citation statements)

References 2 publications

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“…It has been suggested that this locus represents the largest particle with this particular velocity (Ref. 115).…”

Section: Detecting the Frequency Shift By Means Of A Narrow Passband mentioning

confidence: 94%

Survey of Instrumentation Applicable to the Study of Rocket Exhaust Plumes

Fisher¹

1971

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“…It has been suggested that this locus represents the largest particle with this particular velocity (Ref. 115).…”

Section: Detecting the Frequency Shift By Means Of A Narrow Passband mentioning

confidence: 94%

Survey of Instrumentation Applicable to the Study of Rocket Exhaust Plumes

Fisher¹

1971

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“…Doppler systems have been extensively used in water and air flow studies (Greated 1970, Jackson andPaul 1971) and in particular by a group (James et al 1967) studying particle velocities in two-phase nozzle expansion processes. In the latter study, the flow was supersonic and the velocity and related Doppler frequency shift was too high for electronic measurement, and so a Fabry-Perot scanning interferometer was used for direct measurement of the scattered light frequency.…”

Section: Techniques For Measuring Particle Velocitiesmentioning

confidence: 99%

Measurements of individual alumina particle velocities and the relative slip of different-sized particles in a vertical gas - solid suspension flow using a laser - anemometer system

Arundel

Hobson

Lalor

et al. 1974

J. Phys. D: Appl. Phys.

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Particle velocities in a vertically upward gas-solid suspension flow have been measured using a laser-Doppler anemometer system. The electronic signal-processing equipment enables individual particle slip velocities to be measured, which in turn allows mixtures of different-sized particles to be successfully studied. Alumina particles in the size range 15-200 μm were used. In laminar pipe flow of fine particles (15 μm) the particle velocity profile is parabolic, but with increasing pipe Reynolds' number the profile becomes flatter. Near the pipe wall smaller particles were unexpectedly found to have greater slip than larger particles. Reasonable agreement was found between the measured centre-line slip velocities and those computed by extensive theoretical considerations. For alumina particles in excess of 30 μm diameter, Stokes' law is no longer applicable, and great care must be taken in order to obtain an accurate estimation of the slip.

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“…However, the measuring equipment easily interferes with the flow rate of the point to be measured. Laser Doppler velocimetry (LDV) is a noninvasive technique for measuring the speed of moving solid-state surfaces or particle velocity in a fluid by laser interferometry [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Researchers continuously develop and design LDV devices suitable for different applications [15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Laser Velocimetry for the In Situ Sensing of Deep-Sea Hydrothermal Flow Velocity

Sun,

Zhang,

et al. 2023

Sensors

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Laser Doppler velocimetry (LDV) based on a differential laser Doppler system has been widely used in fluid mechanics to measure particle velocity. However, the two outgoing lights must intersect strictly at the measurement position. In cross-interface applications, due to interface effects, two beams of light become easily disjointed. To address the issue, we present a laser velocimeter in a coaxial arrangement consisting of the following components: a single-frequency laser (wavelength λ = 532 nm) and a Twyman–Green interferometer. In contrast to previous LDV systems, a laser velocimeter based on the Twyman–Green interferometer has the advantage of realizing cross-interface measurement. At the same time, the sensitive direction of the instrument can be changed according to the direction of the measured speed. We have developed a 4000 m level laser hydrothermal flow velocity measurement prototype suitable for deep-sea in situ measurement. The system underwent a withstand voltage test at the Qingdao Deep Sea Base, and the signal obtained was normal under a high pressure of 40 MPa. The velocity contrast measurement was carried out at the China Institute of Water Resources and Hydropower Research. The maximum relative error of the measurement was 8.82% when compared with the acoustic Doppler velocimeter at the low-speed range of 0.1–1 m/s. The maximum relative error of the measurement was 1.98% when compared with the nozzle standard velocity system at the high-speed range of 1–7 m/s. Finally, the prototype system was successfully evaluated in the shallow sea in Lingshui, Hainan, with it demonstrating great potential for the in situ measurement of fluid velocity at marine hydrothermal vents.

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A laser-Doppler technique for the measurement of particle velocity.

Cited by 21 publications

References 2 publications

Survey of Instrumentation Applicable to the Study of Rocket Exhaust Plumes

Survey of Instrumentation Applicable to the Study of Rocket Exhaust Plumes

Measurements of individual alumina particle velocities and the relative slip of different-sized particles in a vertical gas - solid suspension flow using a laser - anemometer system

Laser Velocimetry for the In Situ Sensing of Deep-Sea Hydrothermal Flow Velocity

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