URL: https://www.nature.com/articles/s41598-021-89949-z
Abstract: Granular
multiparticle ensembles are of interest from fundamental
statistical viewpoints as well as for the understanding of
collective processes in industry and in nature. Extraction of
physical data from optical observations of three-dimensional
(3D) granular ensembles poses considerable problems.
Particle-based tracking is possible only at low volume
fractions, not in clusters. We apply shadow-based and
feature-tracking methods to analyze the dynamics of granular
gases in a container with vibrating side walls under
microgravity. In order to validate the reliability of these
optical analysis methods, we perform numerical simulations of
ensembles similar to the experiment. The simulations’ output is
graphically rendered to mimic the experimentally obtained
images. We validate the output of the optical analysis methods
on the basis of this ground truth information. This approach
provides insight in two interconnected problems: the
confirmation of the accuracy of the simulations and the test of
the applicability of the visual analysis. The proposed approach
can be used for further investigations of dynamical properties
of such media, including the granular Leidenfrost effect,
granular cooling, and gas-clustering transitions.