Determining candidate particles with centroid DT method in RM-PTV

To improve the convenience of the relaxation based particle tracking velocimetry (RM-PTV) in obtaining the instantaneous flow structure, a centroid Delaunay triangulation (DT) based technique was proposed to determine candidate particles for the target particles in the matching process, and typical self-defined particle images and standard particle images were analyzed to test the validity of the new method. The results show that the centroid DT method can select the candidate particles effectively and conveniently. Moreover, consideration is given to balance accuracy and efficiency, and the previous estimation of the flow field can be avoided, which makes the application of RM-PTV more independent, especially for the complicated flow situation and inexperienced users.