Abstract
Time dependent observations of point-to-point correlations of the velocity vector field (structure functions) are necessary to model and understand fluid flow around complex objects. Using thermal gradients, we observed fluid flow by recording fluorescence of He2∗ excimers produced by neutron capture throughout a ~ cm3 volume. Because the photon emitted by an excited excimer is unlikely to be recorded by the camera, the techniques of particle tracking (PTV) and particle imaging (PIV) velocimetry cannot be applied to extract information from the fluorescence of individual excimers. Therefore, we applied an unsupervised machine learning algorithm to identify light from ensembles of excimers (clusters) and then tracked the centroids of the clusters using a particle displacement determination algorithm developed for PTV.
| Original language | English |
|---|---|
| Article number | 20383 |
| Journal | Scientific Reports |
| Volume | 12 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2022 |
Funding
Discussions with J. Hodges (ORNL), Dr. M. Doucet (ORNL) and Prof. A.G. Del Maestro (UTK) are gratefully acknowledged. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. ORNL is managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. X.W. acknowledges support from the Shull Wollan Center Graduate Research Fellowship program and the Graduate Advancement, Training and Education program of University of Tennessee. W.G. acknowledges the support from the National Science Foundation under Grant No. DMR-2100790 and the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-1644779 and the state of Florida. Discussions with J. Hodges (ORNL), Dr. M. Doucet (ORNL) and Prof. A.G. Del Maestro (UTK) are gratefully acknowledged. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. ORNL is managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. X.W. acknowledges support from the Shull Wollan Center Graduate Research Fellowship program and the Graduate Advancement, Training and Education program of University of Tennessee. W.G. acknowledges the support from the National Science Foundation under Grant No. DMR-2100790 and the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-1644779 and the state of Florida.