Tomo-PIV Measurements in a Refractive Index Matched (RIM) Flow

Refractive index matched (RIM) flow facilities are used to mitigate optical distortions and enable PIV measurements about complex geometries. A comprehensive assessment of planar-PIV performance when viewing through transparent acrylic and urethane models in a sodium iodide (NaI) RIM facility at Notre Dame was provided in Blois et al. 2020. In the current work, tomo-PIV performance in the RIM facility is assessed. Due to the number of cameras required for a tomo-PIV measurement, the direct, instantaneous measurement comparisons that were performed in the prior work are not practical. Therefore, unique data sets obtained with and without an acrylic model in the optical path are compared. Performance metrics include calibration disparity, reconstructed volume characteristics, and ensemble flow statistics.