Endoscopic Stereoscopic Particle Image Velocimetry (PIV)

Stereo Particle Image Velocimetry (SPIV) is a non-invasive, optical measurement technique that can determine the three components of instantaneous velocity vectors in the measurement plane.

Field of Application

  • non-contact measurement of velocity fields in turbomachinery
  • due the endoscopic design, no major interventions in the housing for optical access (windows) are necessary
  • measurement of all three components of local flow velocities (in-place)

Description

Two cameras each take two images of a particle-laden flow.

Evaluation and back transformation of the images yield the complete velocity field in the measuring plane. This allows large-scale investigations of unsteady flow structures as well as the determination of the steady-state flow field. At TFD, SPIV methods with purely endoscopic access are currently used in turbomachinery.

Advantages of the endoscopic stereo PIV system over other optical measurement methods are:

  • small optical access,
  • Determination of a velocity field (areal measurement),
  • Determination of all three velocity components with moderate measurement duration.

In-house expansion of the system at TFD:

Use of endoscopes for light section generation and image acquisition.

Measurement parameter

  • Flow velocity
Picture - Principle sketch endoscopic PIV Picture - Principle sketch endoscopic PIV Picture - Principle sketch endoscopic PIV
Principle sketch endoscopic PIV
Picture - Endoscopic stereo PIV applied to the air turbine Picture - Endoscopic stereo PIV applied to the air turbine Picture - Endoscopic stereo PIV applied to the air turbine
Endoscopic stereo PIV applied to the air turbine
Picture -Endoscopic stereo PIV in a turbo machine Picture -Endoscopic stereo PIV in a turbo machine Picture -Endoscopic stereo PIV in a turbo machine
Endoscopic stereo PIV in a turbo machine