Miller, Ryan Michael.
Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows.
Degree: PhD, Chemical Engineering, 2004, Georgia Tech
A suspension flow model based on the "suspension balance" approach has been developed. This work modifies the model to allow the solution of suspension flows under general flow conditions. This requires the development of a frame-invariant constitutive model for the particle stress which can take into account the spatially-varying local kinematic conditions. The mass and momentum balances for the bulk suspension
and particle phase are solved numerically using a finite volume method. The particle stress is based upon the computed rate of strain and the local kinematic conditions. A nonlocal stress
contribution corrects the continuum approximation of the particle phase for finite particle size effects. Local kinematic conditions are accounted through the local ratio of rotation to extension in the flow field. The coordinates for the stress definition are the local principal axes of the rate of strain field.
The developed model is applied to a range of problems. (i) Axially-developing conduit flows are computed using both the full two-dimensional solution and the more computationally
efficient "marching" method. The model predictions are compared to experimental results for cross-stream particle concentration profiles and axial development lengths. (ii) Model
predictions are compared to experiments for wide-gap circular Couette flow of a concentrated suspension in a shear-thinning liquid. With minor modification, the suspension flow model predicts the major trends and results observed in this flow. (iii) Comparisons are made to experiments for an axisymmetric contraction-expansion. Model predictions for a two-dimensional planar contraction flow test the influence of model formulation. The variation of the magnitude of an isotropic particle normal stress with local kinematic conditions and anisotropy in the
in-plane normal stresses are both explored. The formulation of the particle phase stress is found to have significant effects on the solid fraction and velocity. (iv) Finally, for a rectangular
piston-driven flow and an obstructed channel flow, a "computational suspension dynamics" study explores the effect of particle migration on the bulk flow field, system pressure drop
and particle phase composition.
Advisors/Committee Members: Forney, Larry (Committee Co-Chair), Morris, Jeffrey F. (Committee Co-Chair), Carr, Wallace W. (Committee Member), Koros, William J. (Committee Member), Wick, Timothy M. (Committee Member), Yiacoumi, Sotira Z. (Committee Member), Yoda, Minami (Committee Member).
Subjects/Keywords: Two-phase flow; Suspension flow; Frame-invariant rheology; Finite volume method; Shear-induced migration; Suspension balance model; Shear flow; Finite volume method; Two-phase flow; Rheology; Continuum mechanics
to Zotero / EndNote / Reference
APA (6th Edition):
Miller, R. M. (2004). Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/4864
Chicago Manual of Style (16th Edition):
Miller, Ryan Michael. “Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows.” 2004. Doctoral Dissertation, Georgia Tech. Accessed April 16, 2021.
MLA Handbook (7th Edition):
Miller, Ryan Michael. “Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows.” 2004. Web. 16 Apr 2021.
Miller RM. Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows. [Internet] [Doctoral dissertation]. Georgia Tech; 2004. [cited 2021 Apr 16].
Available from: http://hdl.handle.net/1853/4864.
Council of Science Editors:
Miller RM. Continuum Modeling of Liquid-Solid Suspensions for Nonviscometric Flows. [Doctoral Dissertation]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/4864