This sub-collection contains the processed PIV velocity fields, saved as Matlab .mat files.  Data for acceleration over one chord is in 'a1cvels', and for acceleration over six chords in 'a6cvels'.

Each file contains four variables: x, y, u and v.

x and y are 2D arrays containing data-point coordinates, using the same orientation as shown in the paper (cf. figure 1).  The first array index corresponds to the y direction, and the second to the x direction.  The initial position of the plate centre, deduced from the tracking analysis, is at x = 0.0995m and y = -0.038m.

u and v are 3D arrays containing, respectively, the x- and y-direction velocity data.  Their first two indices correspond to those of x and y; the third index specifies the time.  Denoting this index as 'itime', the elapsed time since start of motion is given by:

(itime - 0.5)/fs - t0,

where fs = 100Hz is the PIV frame rate, and

t0 = 0.0414s for the one-chord acceleration case;

t0 = -0.0242s for the six-chord acceleration case.

Spurious velocity data is flagged by setting both components to zero.