Random loose packing of small particles with liquid cohesion |
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| Authors: | Hongsheng Chen Wenwei Liu Shuiqing Li |
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| Affiliation: | 1. Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Dept. of Energy and Power Engineering, Tsinghua University, Beijing, 100084 China;2. Dept. of Chemical and Process Engineering, University of Surrey, Guildford, GU2 7XH U.K. |
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| Abstract: | Random packing of wet grains is numerically investigated using a multiscale discrete element method. The cohesion between wet grains is evaluated by the Weber number, with which the macroscopic and microscopic properties of wet packing are compared with those of dry systems. The effect of capillary force on wet packing partially resembles that of van der Waals force on the dry adhesive packing, because both packing fraction (ϕ) and coordination number (Z) of wet packing decrease with increasing surface tension, following a Boltzmann-like exponential decay that leads to a metastable state with ϕ ≈ 0.37 and Z ≈ 3.8. The decay processes of wet grains, however, are much faster than that of dry ones due to the additional liquid-phase viscous dissipation. Moreover, in the cases of strong cohesion, the relationship between Z and ϕ can be well interpreted by the Edwards' ensemble theory, while those with weak cohesion follow an exponential formula instead. © 2018 American Institute of Chemical Engineers AIChE J, 65: 500–511, 2019 |
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| Keywords: | random packing liquid bridge microparticle discrete element method |
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