Rolie-Poly fluid flowing through constrictions: Two distinct instabilities
Elastic instabilities of entangled polymer melts are common in industrial processes but the physics responsible is not well understood. We present a numerical linear stability study of a molecular-based constitutive model which grants us physical insight into the underlying mechanics involved. Two c...
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| Format: | Journal article |
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2012
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| _version_ | 1797066210416787456 |
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| author | Reis, T Wilson, H |
| author_facet | Reis, T Wilson, H |
| author_sort | Reis, T |
| collection | OXFORD |
| description | Elastic instabilities of entangled polymer melts are common in industrial processes but the physics responsible is not well understood. We present a numerical linear stability study of a molecular-based constitutive model which grants us physical insight into the underlying mechanics involved. Two constriction flows are considered - one shear dominated, the other extension dominated - and two distinct instabilities are found. The influence of the molecular structure and the behaviour of the polymer dynamics are investigated and in both cases chain relaxation and orientation play a crucial role. Additionally, convective-constraint release is also shown to be critical, but with a contrasting effect in the two flows: when the molecular weight is high, slow release is found to be stabilising in the extension dominated constriction but destabilising in the shear dominated flow. This suggests a molecular-based physical interpretation of the underlying mechanisms responsible for flow instabilities. |
| first_indexed | 2024-03-06T21:39:10Z |
| format | Journal article |
| id | oxford-uuid:474e25cc-5ea0-435c-95c9-8692cd0a7a74 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T21:39:10Z |
| publishDate | 2012 |
| record_format | dspace |
| spelling | oxford-uuid:474e25cc-5ea0-435c-95c9-8692cd0a7a742022-03-26T15:19:24ZRolie-Poly fluid flowing through constrictions: Two distinct instabilitiesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:474e25cc-5ea0-435c-95c9-8692cd0a7a74Mathematical Institute - ePrints2012Reis, TWilson, HElastic instabilities of entangled polymer melts are common in industrial processes but the physics responsible is not well understood. We present a numerical linear stability study of a molecular-based constitutive model which grants us physical insight into the underlying mechanics involved. Two constriction flows are considered - one shear dominated, the other extension dominated - and two distinct instabilities are found. The influence of the molecular structure and the behaviour of the polymer dynamics are investigated and in both cases chain relaxation and orientation play a crucial role. Additionally, convective-constraint release is also shown to be critical, but with a contrasting effect in the two flows: when the molecular weight is high, slow release is found to be stabilising in the extension dominated constriction but destabilising in the shear dominated flow. This suggests a molecular-based physical interpretation of the underlying mechanisms responsible for flow instabilities. |
| spellingShingle | Reis, T Wilson, H Rolie-Poly fluid flowing through constrictions: Two distinct instabilities |
| title | Rolie-Poly fluid flowing through constrictions: Two distinct
instabilities |
| title_full | Rolie-Poly fluid flowing through constrictions: Two distinct
instabilities |
| title_fullStr | Rolie-Poly fluid flowing through constrictions: Two distinct
instabilities |
| title_full_unstemmed | Rolie-Poly fluid flowing through constrictions: Two distinct
instabilities |
| title_short | Rolie-Poly fluid flowing through constrictions: Two distinct
instabilities |
| title_sort | rolie poly fluid flowing through constrictions two distinct instabilities |
| work_keys_str_mv | AT reist roliepolyfluidflowingthroughconstrictionstwodistinctinstabilities AT wilsonh roliepolyfluidflowingthroughconstrictionstwodistinctinstabilities |