Measurement of acceleration and multiple velocity components using a laser Doppler velocity profile sensor

C. Bayer, K. Shirai, L. Büttner, J. Czarske

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

For the investigation of turbulent flows, the measurement of Lagrangian acceleration is of great interest as it represents a direct component of the Navier-Stokes equations. The presented sensor is based on the common laser Doppler technique, but offers in addition combined high spatial resolution in the micrometre range and the possibility of measuring the velocity component along the optical axis. As a result of the sensor setup, signals of particles with inclined trajectories show frequency modulation within a single burst similar to the signal of an accelerated particle. A model-based approach to distinguish between both quantities is presented, and a signal processing technique based on the Hilbert transform has been developed. The processing is comparatively fast and showed good agreement with preset values, even for signals of poor quality. The variance of velocity and acceleration measurements nearly reaches the Cramér-Rao lower bound. Experimental verification is done by the measurement of a harmonic oscillator with known parameters and a stagnation flow within a free jet.

Original languageEnglish
Article number055401
JournalMeasurement Science and Technology
Volume19
Issue number5
DOIs
Publication statusPublished - 2008 May 1

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Keywords

  • Flow acceleration/velocity measurement
  • Lagrangian acceleration
  • Laser Doppler anemometry (LDA LDV)
  • Laser Doppler profile sensor
  • Signal processing
  • Turbulence research

ASJC Scopus subject areas

  • Instrumentation
  • Engineering (miscellaneous)
  • Applied Mathematics

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