Performing Particle Image Velocimetry (PIV) measurements within multi-stage turbomachinery is difficult due to the optical obstruction to the illuminating sheet and to the camera caused by the blades. In order to overcome this problem, a refractive index matched facility is constructed. The test section contains a two-stage axial turbomachine with second stage rotor and stator blades that are made of transparent acrylic. Their refractive index is matched with a 62 % by weight solution of Sodium Iodide in water as the working fluid. This setup allows full optical access to the entire rotor and stator passages without the laser sheet being reflected, blocked or scattered.
Our research focuses on:
  • 2D and Stereoscopic PIV measurements within an entire stage
  • Wake-wake, wake-boundary layer, wake-tip-vortex interactions
  • Wake-blade, tip-vortex-blade interactions
  • Average-passage flow fields and deterministic stress distributions
  • Dynamics of deterministic stresses
  • Turbulent vs. Deterministic stress comparisons
  • Structure of turbulence within rotor wakes
  • Stability of wakes in swirling flows