dorsal/arxiv
View SchemaA mechanism for oscillatory instability in viscoelastic cross-slot flow
| Authors | Li Xi, Michael D. Graham |
|---|---|
| Categories | |
| ArXiv ID | physics/0703262 |
| URL | https://arxiv.org/abs/physics/0703262 |
Abstract
Interior stagnation point flows of viscoelastic liquids arise in a wide variety of applications including extensional viscometry, polymer processing and microfluidics. Experimentally, these flows have long been known to exhibit instabilities, but the mechanisms underlying them have not previously been elucidated. We computationally demonstrate the existence of a supercritical oscillatory instability of low-Reynolds number viscoelastic flow in a two-dimensional cross-slot geometry. The fluctuations are closely associated with the "birefringent strand" of highly stretched polymer chains associated with the outflow from the stagnation point at high Weissenberg number. Additionally, we describe the mechanism of instability, which arises from the coupling of flow with extensional stresses and their steep gradients in the stagnation point region.
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"date_created": "2026-03-02T18:01:17.428000Z",
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"abstract": "Interior stagnation point flows of viscoelastic liquids arise in a wide\nvariety of applications including extensional viscometry, polymer processing\nand microfluidics. Experimentally, these flows have long been known to exhibit\ninstabilities, but the mechanisms underlying them have not previously been\nelucidated. We computationally demonstrate the existence of a supercritical\noscillatory instability of low-Reynolds number viscoelastic flow in a\ntwo-dimensional cross-slot geometry. The fluctuations are closely associated\nwith the \"birefringent strand\" of highly stretched polymer chains associated\nwith the outflow from the stagnation point at high Weissenberg number.\nAdditionally, we describe the mechanism of instability, which arises from the\ncoupling of flow with extensional stresses and their steep gradients in the\nstagnation point region.",
"arxiv_id": "physics/0703262",
"authors": [
"Li Xi",
"Michael D. Graham"
],
"categories": [
"physics.flu-dyn"
],
"title": "A mechanism for oscillatory instability in viscoelastic cross-slot flow",
"url": "https://arxiv.org/abs/physics/0703262"
},
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