What is Power-law fluid?

In continuum mechanics, a power-law fluid, or the Ostwald–de Waele relationship, is a type of generalized Newtonian fluid for which the shear stress, τ, is given by

where:

The quantity

represents an apparent or effective viscosity as a function of the shear rate. The value of K and n can be obtained from the graph of log ⁡ {\displaystyle \log} and log ⁡ {\displaystyle \log \left}. The slope line gives the value of n – 1, from which n can be calculated. The intercept at log ⁡ = 0 {\displaystyle \log \left=0} gives the value of K.