Flow past a swirler grid - PIV data from wind tunnel at Re 1.3 × 10^4 and 2.7 × 10^4

Particle Image Velocimetry (PIV) measurement of flow past a swirler grid.

This grid is designed to produce a regular system of clock-wise and anti-clock-wise vortices, which alternate in a same way as black and white squares on a chessboard. These longitudinal vortices are relatively stable and they play as a energy source at larger distances past the grid. Therefore, the maximum of turbulent kinetic energy (TKE) lies in the distance of ~ 10 × M (the mesh parameter).

- File "MeasuredPlanes.png" for general overview. The PIV is in Stereo configuration (so called 2D 3C).

- File "SwirlerGrid.scad" is the geometry (CAD), to open and modify that file, You will need open-source program OpenSCAD, https://openscad.org/. The geometry is described in more details in a function sample: https://www.kke.zcu.cz/cs/Research/function_samples (in Czech language)

- File "StereoPIV.zip" contains the measured data. They are organized in folders named e.g. "t05msX02", where "t05ms" means wind tunnel velocity of 5 m/s and "X02M" signifies the stream-wise distance in multiplies of M. Each such folder contains about 500 individual snapshots in ".csv" files, which are exported from Dantec Dynamic Studio. The data start at line no. 10. The column description is in line no. 9, velocity data are in columns 5 - 7, where 5th column (headed "U") represents the velocity in horizontal direction, i.e. y-axis in Figure "MeasuredPlanes.png"; 6th column (headed "V") is vertical z-velocity and 7th column (headed "W") is the stream-wise x-component.