TY - JOUR

T1 - Non-Newtonian flow instability in a channelwith a sudden expansion

AU - Neofytou, Panagiotis

AU - Drikakis, Dimitris

PY - 2003/4/3

Y1 - 2003/4/3

N2 - The paper presents a numerical investigation of instabilities occurring in non-Newtonian flows through a sudden expansion. Three non-Newtonian models, used in the literature for simulating the rheological behaviour of blood, are employed, namely the Casson, Power-Law, and Quemada models. The computations reveal that similar to Newtonian flow through a suddenly expanded channel, an instability also occurs in non-Newtonian flows. The instability is manifested by a symmetry breaking of the flow separation. The onset of the instability depends on the specific parameters involved in each model’s constitutive equation. The investigation encompasses a parametric study for each model, specifically the critical values at which transition from stable to unstable flow occurs. Due to the fact that for each of the Casson and Quemada models, two characteristic flow parameters exist, the relation between the critical values for each of these parameters is also examined.

AB - The paper presents a numerical investigation of instabilities occurring in non-Newtonian flows through a sudden expansion. Three non-Newtonian models, used in the literature for simulating the rheological behaviour of blood, are employed, namely the Casson, Power-Law, and Quemada models. The computations reveal that similar to Newtonian flow through a suddenly expanded channel, an instability also occurs in non-Newtonian flows. The instability is manifested by a symmetry breaking of the flow separation. The onset of the instability depends on the specific parameters involved in each model’s constitutive equation. The investigation encompasses a parametric study for each model, specifically the critical values at which transition from stable to unstable flow occurs. Due to the fact that for each of the Casson and Quemada models, two characteristic flow parameters exist, the relation between the critical values for each of these parameters is also examined.

KW - separated flow

KW - numerical simulation

KW - non-Newtonian flow

KW - blood flow

KW - bifurcation phenomena

UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0038694746&partnerID=40&md5=7e8b3d649211ce2872e687c0bb9fb41c

U2 - 10.1016/S0377-0257(03)00041-7

DO - 10.1016/S0377-0257(03)00041-7

M3 - Article

VL - 111

SP - 127

EP - 150

JO - Journal of Non-Newtonian Fluid Mechanics

JF - Journal of Non-Newtonian Fluid Mechanics

SN - 0377-0257

IS - 2-3

ER -