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Particle‐Induced Limits of Accuracy in Laser Doppler Anemometry
Author(s) -
Ruck Bodo,
Pavlovski Boris
Publication year - 1993
Publication title -
particle and particle systems characterization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 56
eISSN - 1521-4117
pISSN - 0934-0866
DOI - 10.1002/ppsc.19930100305
Subject(s) - laser doppler velocimetry , optics , doppler effect , signal (programming language) , laser , particle (ecology) , volume (thermodynamics) , physics , flow (mathematics) , mechanics , computer science , geology , medicine , blood flow , oceanography , quantum mechanics , astronomy , programming language
Laser Doppler anemometry (LDA) is one of the most advanced optical measuring techniques for flow velocities and is widely used in industrial and academic laboratories. Based on numerous applications in the past, there is no doubt that LDA is one of the most accurate flow measuring techniques. However, recent investigations have shown that the period lengths of LDA signal bursts are not as constant as one might expect within the individual burst. This can induce an additional scatter in the signal frequency and in the determination of flow velocity from individual bursts. This paper describes experimental investigations which show qualitatively and quantitatively that the particle passage through the laser beams shortly before the point of intersection, i. e. the LDA measuring volume, yields a distorted LDA fringe pattern. The latter results in a scatter of the measured velocity data for those particles passing the center of the measuring volume at the same time.