Vortex breakdown in swirling pipe flow of fluids with shear-dependent viscosity

Thornhill, Thomas O, Petit, Tom, Poole, Robert J ORCID: 0000-0001-6686-4301 and Dennis, David JC ORCID: 0000-0003-0214-7885 (2018) Vortex breakdown in swirling pipe flow of fluids with shear-dependent viscosity. PHYSICS OF FLUIDS, 30 (11). p. 114107.

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Abstract

<jats:p>Laminar pipe flow with a controllable wall swirl has been studied both numerically and experimentally to explore the behavior of inelastic shear-dependent fluids. The pipe consists of two smoothly joined sections that can be rotated independently about the same axis. The circumstance of flow entering a stationary pipe from a rotating pipe (decaying swirl) has been investigated. Numerical parametric studies using both a power-law model and a simplified Carreau model are conducted to investigate the effect of shear-thinning and shear-thickening on the flow structure and the critical swirl ratio required to induce the breakdown at a range of Reynolds numbers. A new method of scaling (i.e., a new Reynolds number) is presented that accounts for the shear-dependent viscosity. Using this Reynolds number, the data for all fluids (shear-thickening, Newtonian, and shear-thinning) approximately collapses. Experimental visualisations using an aqueous solution of xantham gum confirm the conclusions drawn from the numerical results.</jats:p>

Item Type:	Article
Depositing User:	Symplectic Admin
Date Deposited:	03 Dec 2018 15:57
Last Modified:	10 Jul 2023 15:35
DOI:	10.1063/1.5057409
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3029424