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Main Authors: Lester, Daniel R., Buscall, Richard
Format: Preprint
Published: 2014
Subjects:
Online Access:https://arxiv.org/abs/1409.8397
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author Lester, Daniel R.
Buscall, Richard
author_facet Lester, Daniel R.
Buscall, Richard
contents The batch settling test is widely used to estimate the compressive rheology of strongly flocculated colloidal suspensions, in particular the compressive yield strength and hydraulic permeability. Recently it has been discovered that wall adhesion effects in these tests may be significantly greater than previously appreciated, which can introduce unbounded errors in the estimation of these rheological functions. Whilst a methodology to solve the underlying static problem and correct for wall adhesion effects has been developed, this method is quite complex and unwieldy, involving solution of a 2D hyper-elastic constitutive model for strong colloidal gels. In this paper we develop a highly simplified 1D visco-plastic approximation to the hyper-elastic model which admits analytic expressions for the equilibrium solids concentration profile and bed height. These expressions facilitate robust estimation of the compressive yield and wall adhesion strength via nonlinear regression of experimental data in the presence of small measurement errors.
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id arxiv_https___arxiv_org_abs_1409_8397
institution arXiv
publishDate 2014
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spellingShingle Correction of Wall Adhesion Effects in Batch Settling of Strong Colloidal Gels
Lester, Daniel R.
Buscall, Richard
Soft Condensed Matter
The batch settling test is widely used to estimate the compressive rheology of strongly flocculated colloidal suspensions, in particular the compressive yield strength and hydraulic permeability. Recently it has been discovered that wall adhesion effects in these tests may be significantly greater than previously appreciated, which can introduce unbounded errors in the estimation of these rheological functions. Whilst a methodology to solve the underlying static problem and correct for wall adhesion effects has been developed, this method is quite complex and unwieldy, involving solution of a 2D hyper-elastic constitutive model for strong colloidal gels. In this paper we develop a highly simplified 1D visco-plastic approximation to the hyper-elastic model which admits analytic expressions for the equilibrium solids concentration profile and bed height. These expressions facilitate robust estimation of the compressive yield and wall adhesion strength via nonlinear regression of experimental data in the presence of small measurement errors.
title Correction of Wall Adhesion Effects in Batch Settling of Strong Colloidal Gels
topic Soft Condensed Matter
url https://arxiv.org/abs/1409.8397