Multi-sheet illumination and consecutive overlapping 2D-2C PIV acquisition for enhanced access to boundary layer flows around obstructive opaque objects

In experiments based on laser-diagnostic techniques, the field of view of the imaging can present limitations in the size of the flow area that can be investigated as well as the resolution of the acquisition. This is especially pertinent to external flows past objects where both the information in the boundary layer and the far field are important in understanding the physics of the problem. In this work, we introduce a variation in the experimental technique using a single laser and multiple light sheets with one camera, to perform highresolution 2D-2C PIV measurements of relatively large opaque samples and areas of interest (compared with the available field of view of the camera). Here we focus on single-body, opaque samples such as hydrofoils, and multi-body samples with members arranged at structured distances from each other (suspended and fixed in the water from above). This experimental procedure aims to provide a baseline method to study the boundary layers and flows over the entirety of samples with complicated geometries and arrangements and provide statistical data for the theoretical and numerical modeling of such flows.