Summary of approaches to modelling in-situ rheology

In order to analyse the in-situ rheology of polymer solutions, an approach under one of the following headings may be considered  

Each of the above will be considered in turn, and some of the advantages and disadvantages of each approach will be indicated. 

Approach (iii) listed above refers to the use of effective medium theory (Kirkpatrick, 1973 Koplik, 1982 Levine and Cuthiell, 1986) for calculating certain average flow properties in idealised porous media models—usually simple networks. Cannella et al (1988) have recently applied this approach to the flow of power law fluids through networks of capillaries. They use this method to derive an expression for the apparent viscosity of the polymer in the porous medium which has the same overall form as the capillary bundle expression (e.g. Equation 6.18). They then adjusted the parameters in the effective medium formula in order to match their particular form of the capillary bundle formula with C = 6 (Equation 6.18). The values of the effective medium parameters are physically interpretable, and Cannella et al (1988) deduced from these that the effective radius for the flow of a power law fluid is larger than that for the flow of a Newtonian fluid. They also 

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POLYMER RHEOLOGY IN POROUS MEDIA 6.5.1 Summary of approaches to modelling in-situ rheology... 

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