Near-Wall Study of a Turbulent Boundary Layer Using High-Speed Tomo-PIV

The fundamental study of the near-wall structure organization in turbulent flows is crucial to understand the self-generation process of turbulence. To investigate such phenomena, an experiment of high-repetition, 6-camera tomo-PIV in a boundary layer was performed. Vector fields generated from BIMART high-quality reconstructed volumes resulted in low measurement uncertainties. The comparison of turbulence statistics from tomographic PIV and hot-wire anemometer data shows an excellent agreement. Preliminary vortex detection from Q-criterion is presented and allows the identification of dispersed vortices around the low-speed streaks in the boundary layer. Nevertheless an accurate identification of turbulent structures is not yet achieved. The postprocessing is being reviewed and the discussion of the interaction and evolution of turbulent structures will be addressed in a future paper.