The role of fluid flow in the dynamics of active nematic defects
We adapt the Halperin–Mazenko formalism to analyze two-dimensional active nematics coupled to a generic fluid flow. The governing hydrodynamic equations lead to evolution laws for nematic topological defects and their corresponding density fields. We find that ±1/2 defects are propelled by the local...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2021-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/abe8a8 |
| _version_ | 1797750168690360320 |
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| author | Luiza Angheluta Zhitao Chen M Cristina Marchetti Mark J Bowick |
| author_facet | Luiza Angheluta Zhitao Chen M Cristina Marchetti Mark J Bowick |
| author_sort | Luiza Angheluta |
| collection | DOAJ |
| description | We adapt the Halperin–Mazenko formalism to analyze two-dimensional active nematics coupled to a generic fluid flow. The governing hydrodynamic equations lead to evolution laws for nematic topological defects and their corresponding density fields. We find that ±1/2 defects are propelled by the local fluid flow and by the nematic orientation coupled with the flow shear rate. In the overdamped and compressible limit, we recover the previously obtained active self-propulsion of the +1/2 defects. Non-local hydrodynamic effects are primarily significant for incompressible flows, for which it is not possible to eliminate the fluid velocity in favor of the local defect polarization alone. For the case of two defects with opposite charge, the non-local hydrodynamic interaction is mediated by non-reciprocal pressure-gradient forces. Finally, we derive continuum equations for a defect gas coupled to an arbitrary (compressible or incompressible) fluid flow. |
| first_indexed | 2024-03-12T16:28:50Z |
| format | Article |
| id | doaj.art-c8d5ff1c86d94875b2e88e3a0daac8f0 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:28:50Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-c8d5ff1c86d94875b2e88e3a0daac8f02023-08-08T15:35:46ZengIOP PublishingNew Journal of Physics1367-26302021-01-0123303300910.1088/1367-2630/abe8a8The role of fluid flow in the dynamics of active nematic defectsLuiza Angheluta0https://orcid.org/0000-0001-7231-6694Zhitao Chen1M Cristina Marchetti2https://orcid.org/0000-0003-3583-4999Mark J Bowick3https://orcid.org/0000-0003-1716-2754Njord Centre, Department of Physics, University of Oslo , P. O. Box 1048, 0316 Oslo, NorwayDepartment of Physics, University of California Santa Barbara , Santa Barbara, CA 93106, United States of AmericaDepartment of Physics, University of California Santa Barbara , Santa Barbara, CA 93106, United States of AmericaKavli Institute for Theoretical Physics, University of California Santa Barbara , Santa Barbara, CA 93106, United States of AmericaWe adapt the Halperin–Mazenko formalism to analyze two-dimensional active nematics coupled to a generic fluid flow. The governing hydrodynamic equations lead to evolution laws for nematic topological defects and their corresponding density fields. We find that ±1/2 defects are propelled by the local fluid flow and by the nematic orientation coupled with the flow shear rate. In the overdamped and compressible limit, we recover the previously obtained active self-propulsion of the +1/2 defects. Non-local hydrodynamic effects are primarily significant for incompressible flows, for which it is not possible to eliminate the fluid velocity in favor of the local defect polarization alone. For the case of two defects with opposite charge, the non-local hydrodynamic interaction is mediated by non-reciprocal pressure-gradient forces. Finally, we derive continuum equations for a defect gas coupled to an arbitrary (compressible or incompressible) fluid flow.https://doi.org/10.1088/1367-2630/abe8a8active nematicsactive matterdefect dynamics |
| spellingShingle | Luiza Angheluta Zhitao Chen M Cristina Marchetti Mark J Bowick The role of fluid flow in the dynamics of active nematic defects New Journal of Physics active nematics active matter defect dynamics |
| title | The role of fluid flow in the dynamics of active nematic defects |
| title_full | The role of fluid flow in the dynamics of active nematic defects |
| title_fullStr | The role of fluid flow in the dynamics of active nematic defects |
| title_full_unstemmed | The role of fluid flow in the dynamics of active nematic defects |
| title_short | The role of fluid flow in the dynamics of active nematic defects |
| title_sort | role of fluid flow in the dynamics of active nematic defects |
| topic | active nematics active matter defect dynamics |
| url | https://doi.org/10.1088/1367-2630/abe8a8 |
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