Independence improvement for relaxation method based particle tracking velocimetry

The independence of the relaxation method based particle tracking velocimetry (RM-PTV) was improved to obtain the instantaneous flow structure more conveniently. Delaunay triangulation (DT) was employed to determine reference particles which preserve similar motion with target particles and simulation calculation was done for the typical self-defined flow fields. The neighborhood window method was applied to analyze the fake vectors' distribution and magnitude. The results show that DT can effectively determine the reference particles and the improved algorithm reserves the advantages of against noise and calculating "particles having no matched candidate"; fake vectors' distribution and magnitude appear to be quite similar in the two cases when noise and particles having no matched candidate exist. The improved RM-PTV was employed to track trajectories of saltating sand in an atmospheric boundary layer and the results can meet the requirement. It seems that the independence can be improved and the original advantages can be reserved by adopting DT in RM-PTV.