Premium
Screw‐generated forces in granular media: Experimental, computational, and analytical comparison
Author(s) -
Thoesen Andrew,
Ramirez Sierra,
Marvi Hamid
Publication year - 2019
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.16517
Subject(s) - thrust , discrete element method , mechanics , superposition principle , resistive touchscreen , mathematics , structural engineering , engineering , physics , mechanical engineering , mathematical analysis , electrical engineering
This study presents an experimental, computational, and analytical comparison of a submerged, double‐helix Archimedes screw generating propulsive force against a bed of glass beads. Three screws of different pitch lengths were studied. Each screw was tested at six speeds in approximately 10 trials for a total of 180 experimental trials. These experiments were then replicated in EDEM, a discrete element method (DEM) software program. DEM simulation results for thrust forces in the 30–120 rpm regime had a 5%–20% inflation of forces compared to experimental results. These simulations were then compared with resistive force theory (RFT) plate approximation of the screw geometries. We analyze a superposition‐based partition approach to the full‐length screws as well as force generation in shortened, one‐ and two‐blade screws. We find that the force generation is dependent on the flow patterns and cannot be reduced to partitioned approximations as with simple intruders. © 2018 American Institute of Chemical Engineers AIChE J , 65: 894–903, 2019