Open AccessAn expression for the angle of repose of dry cohesive granular materials on Earth and in planetary environments
Author(s) -
Filip Elekes,
Eric J. R. Parteli
Publication year - 2021
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2107965118
Subject(s) - angle of repose , heap (data structure) , granular material , conical surface , physics , van der waals force , mechanics , particle size , classical mechanics , particle (ecology) , geometry , geotechnical engineering , chemistry , mathematics , geology , quantum mechanics , oceanography , algorithm , molecule
Significance The angle between the sloping side of a heap of particles and the horizontal, called angle of repose, is often used to characterize the flowability of granular materials on Earth and planetary environments, such as sand, dust aerosols, and powders. In planetary research, this angle provides an excellent proxy for particle size. The smaller the particle is, the larger the effect of attractive forces between atoms and molecules on the surface of the particles relative to particle weight, the less flowable the material, and the steeper, thus, the angle of repose. We present a model that accurately predicts the angle of repose as a function of particle size, both on Earth and under extraterrestrial gravity.