Particle image velocimetry (PIV) data of flow past a cylinder

The dataset is a MATLAB data file and contains a 2D velocity field over time of flow past a cylinder, acquired with 2D/planar particle image velocimetry (PIV). The experiment was conducted in a recirculating water channel at cylinder Reynolds number Re = 413. The cylinder is finite length, and the PIV data was acquired in a plane at the mid-span. The velocity fields were computed using LaVision DaVis 8.1.2. The frequency of the dataset is 20 Hz. Additional experimental and PIV processing details can be found in J. H. Tu et al, "Spectral analysis of fluid flows using sub-Nyquist-rate PIV data", Experiments in Fluids, 2014. The dataset contains 4 variables: u: velocity in the x-direction (meters per second) v: velocity in the y-direction (meters per second) x: x-coordinate grid (meters) y: y-coordinate grid (meters) Note that some of the values in (u,v) are undefined as NaNs; these regions were masked out prior to PIV processing as they correspond to regions of the flow that are not illuminated by the laser: the cylinder cross-section, and the shadows cast by the cylinder.