Numerical study of driven flows of shear thinning viscoelastic fluids in rectangular cavities

Dalal, Swapnil and Tomar, Gaurav and Dutta, Pradip (2016) Numerical study of driven flows of shear thinning viscoelastic fluids in rectangular cavities. In: JOURNAL OF NON-NEWTONIAN FLUID MECHANICS, 229 . pp. 59-78.

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Abstract

In this work, we present a numerical study of flow of shear thinning viscoelastic fluids in rectangular lid driven cavities for a wide range of aspect ratios (depth to width ratio) varying from 1/16 to 4. In particular, the effect of elasticity, inertia, model parameters and polymer concentration on flow features in rectangular driven cavity has been studied for two shear thinning viscoelastic fluids, namely, Giesekus and linear PTT. We perform numerical simulations using the symmetric square root representation of the conformation tensor to stabilize the numerical scheme against the high Weissenberg number problem. The variation in flow structures associated with merging and splitting of elongated vortices in shallow cavities and coalescence of corner eddies to yield a second primary vortex in deep cavities with respect to the variation in flow parameters is discussed. We discuss the effect of the dominant eigenvalues and the corresponding eigenvectors on the location of the primary eddy in the cavity. We also demonstrate, by performing numerical simulations for shallow and deep cavities, that where the Deborah number (based on convective time scale) characterizes the elastic behaviour of the fluid in deep cavities, Weissenberg number (based on shear rate) should be used for shallow cavities. (C) 2016 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
Publisher:	ELSEVIER SCIENCE BV
Additional Information:	Copy right for this article belongs to the ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Keywords:	Driven rectangular cavity flow; Shear-thinning; Viscoelasticity; Giesekus model; Linear PTT model
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	23 Apr 2016 07:04
Last Modified:	23 Apr 2016 07:04
URI:	http://eprints.iisc.ac.in/id/eprint/53692

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