3D reconstruction of a thin flexible disc in a vortical flow
Résumé
To improve our understanding of how deformable
objects are transported in flows, it is necessary
to develop new experimental tools capable of accurately
measuring the evolution of their deformations.
We present a reconstruction process for sheet-like objects
utilizing Thin-Plate Splines (TPS), providing access
to the object’s 3D position and deformation over
time. We tested the technique on a simple configuration:
a thin-heavy-flexible disc within a vortical flow
driven by impellers in a cubic tank. The vortical flow
field is characterized using Particle Image Velocimetry
(PIV) and is seen to be well approximated as a Lamb-
Oseen vortex within the volume of reconstruction. The
disc is imaged using three cameras, which are calibrated
using the pinhole model. The reconstruction process
uses shape-from-silhouette to define an initial 3D reconstruction,
which is subsequently refined by minimizing
a cost function based on physical and visual criteria.
This process is shown to be generalizable to other thin
geometries, offering a starting point towards studying
the dynamics of more complex sheet-like objects, such
as plastic pollutants and vegetation.
Domaines
Physique [physics]Origine | Fichiers produits par l'(les) auteur(s) |
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