A variational filtration and interpolation technique for PIV employing fluid dynamical constraints

A variational method for post-processing of the velocity fields obtained by particle image velocimetry (PIV) is described. This method allows one to effectively reconstruct the flow field in the areas of the domain where the spurious vectors were discarded either by other filters or manually. If the spurious vectors cannot be removed, they are smoothed in with the surrounding field so that their effect is significantly reduced. The method is based on the application of dynamical constraints such as continuity, smoothness and matching to the original data. The results of the application of the developed algorithm to the velocity fields obtained by PIV in laboratory experiments with quasi-two-dimensional vortex dipoles are discussed.