The instability of non-Newtonian boundary-layer flows over rough rotating disks

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Tarih

2019

Yazarlar

Alqarni, A. A.
Alveroğlu, Burhan
Griffiths, P. T.
Garrett, S. J.

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Elsevier

Erişim Hakkı

info:eu-repo/semantics/openAccess

Özet

We are concerned with the local linear convective instability of the incompressible boundary-layer flows over rough rotating disks for non-Newtonian fluids. Using the Carreau model for a range of shear-thinning and shear-thickening fluids, we determine, for the first time, steady-flow profiles under the partial-slip model for surface roughness. The subsequent linear stability analyses of these flows (to disturbances stationary relative to the disk) indicate that isotropic and azimuthally-anisotropic (radial grooves) surface roughness leads to the stabilisation of both shear-thinning and -thickening fluids. This is evident in the behaviour of the critical Reynolds number and growth rates of both Type I (inviscid cross flow) and Type II (viscous streamline curvature) modes of instability. The underlying physical mechanisms are clarified using an integral energy equation.

Açıklama

Anahtar Kelimeler

Laminar boundary layer, Non-Newtonian, Carreau fluid, Convective instability

Kaynak

Journal Of Non-Newtonian Fluid Mechanics

WoS Q Değeri

Q2

Scopus Q Değeri

Q1

Cilt

273

Sayı

Künye