| Popis: |
A simple model of thixotropy is described which follows the transition in flow properties of a fluid which is highly viscous and highly non-Newtonian at rest and becomes less viscous and less non-Newtonian after shearing. The instantaneous flow properties at any time during shearing are approximated by the power law. For a complete history of the fluid a family of power law flow curves, with a common intersection point at high shear rate, can be approximated. This allows time dependent properties to be represented by changes in the flow behaviour index and to be modelled as a simple, shear rate dependent, rate process. The description can be applied to both breakdown and recovery processes. |
