Fluid Mechanics and Acoustics Laboratory - UMR 5509

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Laboratoire de Mécanique des Fluides et d’Acoustique

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Home > Research Support > Scientific instrumentation > Techniques > PDA - Phase Doppler Anemometry

PDA - Phase Doppler Anemometry

PDA - Phase Doppler Anemometry

The Phase Doppler Anemometry, also called PDA, is an extension of the Laser Doppler Velocimetry, also called LDV. This techniques makes possible the pairing of the particles velocity and diameter measurements. This technique, developed by Durst & Zaré and then improved by Bachalo & Houser, Sullman et al., is the measurements technique the most used to determine simultaneously the size and the velocity of particles considered isotropic, homogeneous and spherical.

Physical principles

  • The phase measurement makes possible to determine the particle diameter.
  • The relation between the phase and the diameter is predicted by geometric optics.
  • The generalised Lorenz-Mie and Debye therories are two theories that enable a faithful modelization of the interaction of a non-magnetic, isotropic, homogeneous and spherical particle with a laser beam.

Concept schematic

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PDA measurements system (Dantec Dynamics)