Bimodal model of concentrated suspension viscosity for distributed particle sizes
- Massachusetts Institute of Technology, Cambridge, MA (United States)
A polydisperse suspension with a particle size distribution from submicron to hundreds of microns is treated as bimodal, wherein it is made up of a colloidal fine fraction and a noncolloidal coarse fraction. The fine fraction imparts to the suspension its non-Newtonian characteristics independently of the coarse fraction, whereas the coarse particles raise the apparent viscosity through hydrodynamic interactions. It is shown that when the particle microstructure is random the contribution to the viscosity of a polymodal coarse fraction is characterized by lubrication concepts with the maximum packing fraction as the scaling parameter. This maximum packing fraction is found equal to the dry random packing fraction divided by a filler dilatancy factor of 1.19. The bimodal model has been successfully applied to bidisperse suspensions with a very large particle size ratio. An inverse procedure is described that makes use of the results from viscosity and dry random packing measurements to divide a continuous size distribution into a colloidal and a noncolloidal fraction.
- Research Organization:
- Argonne National Lab., IL (United States)
- DOE Contract Number:
- FG02-89ER14085
- OSTI ID:
- 102999
- Report Number(s):
- CONF-9404137--; ON: DE94017694
- Country of Publication:
- United States
- Language:
- English
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