Relaxation algorithm-based PTV with dual calculation method and its application in addressing particle saltation

Abstract

This paper proposes a dual calculation method (DCM) that in velocity fields obtained from particle tracking velocimetry detects spurious velocity vectors. The synthetic images were used to test the performance of the DCM. By adding random erasing to the genuine matching data, the influence of noise effect was simulated and analyzed. A comparison with the minimum net-flux method indicates that the DCM is more effective in identifying erroneous vectors as particles having no genuine candidates are more readily identified, thereby, ensuring strong consistent match. The DCM is also found to be more effective in addressing particle saltation, based on the accurately abstracted trajectories, the kinetic parameters of the sand grains are calculated.

Vision-based correspondence using relaxation algorithms for particle tracking velocimetry

“…The proposed algorithm derives from the adaptation of the vision-based feature association concept [15] to PTV [12], the relaxation method-based PTV [6,9] and the dual calculation method [9,16]. Its implementation is hybridized with PIV results in order to drastically reduce the use of arbitrarily chosen parameters.…”

“…Eventually, in a similar manner as in [16] a dual calculation method is applied, i.e. steps 2-6 are repeated by considering the backward tracking from the 'second image' to the 'starting image' to compute the backward pairing matrix M b .…”

“…of correct correspondences No. of actual correspondences (16) precision = No. of correct correspondences No.…”

“…m is obtained (the upperscript b refers to the backward computation). The final pairing matrix M ∈ M m,n is computed as(Jia et al 2015) …”

Detection of river flow slow-down through sensing system and quasi-real time imaging

“…Particle Tracking Velocity (PTV) has been widely used in applications ranging from fluid mechanics to combustion analysis [1]. To obtain a high frame rate capable to capture quickly moving particles within the short exposure time of a high-speed camera the PVT method requires that the flow under investigation is illuminated by a powerful light source.…”