Probing the dynamics of polymer solutions in extensional flow using step strain rate experiments
| Autor: | Tamarapu Sridhar, Nicholas Orr |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Materials science
Strain (chemistry) Applied Mathematics Mechanical Engineering General Chemical Engineering Constitutive equation Flow (psychology) Mechanics Strain rate Condensed Matter Physics Volumetric flow rate Stress (mechanics) Stress relaxation General Materials Science Deformation (engineering) |
| Zdroj: | Journal of Non-Newtonian Fluid Mechanics. 82:203-232 |
| ISSN: | 0377-0257 |
| DOI: | 10.1016/s0377-0257(98)00163-3 |
| Popis: | This paper sets out to examine the response of polymer solutions to time-dependent strain rates. Following a step-change in strain rate, the polymer solution was observed to respond almost instantaneously to the imposed flow rate. Under all extension histories having a positive extension rate that were investigated, the instantaneous stress is proportional to instantaneous strain rate multiplied by a function of the strain. Simulations using the FENE-P model were unable to capture these trends. A pause was introduced in a constant strain rate experiment and revealed that the stress growth upon re-inception of flow was significantly faster predicted by simple constitutive equations. The stress growth depends not only on the current stress and imposed deformation but also on the history of deformation as stored in the configuration distribution of the chain. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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