Steady shear flow of inelastic polymers

Without doubt, the most commonly encountered analytical form of the viscosity-shear rate relationship is the power law model (Bird et al, 1960), which describes the pseudoplastic region. The power law model is sometimes called the law of Ostwald and de Waele (Bird et u/., 1960 Reiner, 1960) and is given by the expression  

A more satisfactory model for these shear regimes is the Carreau equation (Carreau, 1972 Bird et al, 1987a). Here the viscosity function is given by  

Power law ri = Kf- K = constant (cp s ), which is equivalent (0 This is mathematically the simplest 

Bird et ai (1960) n - dimensionless constant, typically in (ii) Unsatisfactory behaviour of this 

Eyring fsinh HoA o ol. I to = a characteristic time (i) Originally derived from the 

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