Small-Scale PB-HTGR Recirculating DEM Pebble Coordinate Data (40,000 pebbles)

A dataset containing the pebble coordinate data for a recirculating, small-scale pebble-bed High Temperature Gas Cooled Reactor (PB-HTGR) created using a Ghastly-generated LAMMPS input file (see the 'recircf2-2m.json) Ghastly input file example in the Ghastly GitHub repository's /examples directory. The simulation time step length is 2.6855275354389e-07 seconds, or approximately 0.27 microseconds. Every 2.5 million simulation steps, pebbles inside the designated discharge zone (the bottom 6 cm of the outlet) are removed and placed at the top of the inlet instantaneously. Then the pebbles are allowed to freefall, and the bed settles under gravity. The coordinates.tar tarball contains a series of txt files named step_[N].txt, where [N] corresponds to the simulation step at which the data file was created. Each file contains the complete coordinate data for all pebbles in the simulation at that point in time. ID refers to the pebble's unqiue ID code, type is the particle's LAMMPS type, x, y, and z are the pebble center coordinates, and i_pass, i_recirc, i_zone, and i_layer are non-physical parameters used to track the randomly-assigned pass number for the pebble, the number of times it has recirculated, the pebble's original radial zone, and the pebble's original axial layer. i_zone and i_layer are generally intended to be used to color the pebbles, acting as a visual guide (like tracer dye in a flow study, for example). The recirculated.tar tarball contains a series of txt files named step_[N].txt, where [N] corresponds to the simulation step at which the data file was created. Each file contains a list of the unique IDs of the pebbles that were selected for recirculation at that simulation step.