Computation of non-similar flow of a magnetic pseudoplastic nanofluid over a circular cylinder with variable thermophysical properties and radiative flux

Beg, OA; Basha, HT; Sivaraj, R; Prasad, VR

Abstract

Generally, in computational thermofluid dynamics, the thermophysical properties of flu-
ids (e.g. viscosity and thermal conductivity) are considered as constant. However, in
many applications, the variability Of these properties plays a significant role in modify-
ing transport characteristics While the temperature difference in the boundary layer is
notable. These include drag reduction in heavy oil transport systems, petroleum purifi-
cation and coating manufacturing. Motivated by the last of these applications, in the
current study, a comprehensive mathematical model is developed to explore the impact of
variable viscosity and variable thermal conductivity characteristics in magnetohydrody-
namic non-Newtonian nanofluid enrobing boundary layer flow over a horizontal circular
cylinder in the presence of cross diffusion (Soret and Dufour effects) and appreciable
thermal radiative heat transfer under a static radial magnetic field. The Williamson
pseudoplastic model is deployed for rheology Of the nanofluid. Buongiornos two com-
ponent model is employed for effects. The dimensionless nonlinear partial
differential equations have been solved by using an implicit finite difference Keller box
scheme. Extensive validation with earlier studies in the absence of nanoscale and vari-
able property effects is included. The influence of notable parameters like Weissenberg
number, variable viscosity, variable thermal conductivity, Soret and Dufour numbers on
heat, mass and momentum characteristics are scrutinized and visualized via graphs and
tables. The outcomes disclcxse that the Williamson nanofluid velocity declines by enhanc-
ing the Lorentz hydromagnetic force in the radial direction. Thermal and nanoparticle
concentration boundary layer thickness are enhanced With greater streamwise coordinate
values. An increase in Dufour number or a decrease in Soret number slightly enhances
the nanofluid temperature and thickens the thermal boundary layer. Flow deceleration is
induced with greater viscosity parameter. Nanofluid temperature is elevated with greater
Weissenberg number and thermophoresis nanoscale parameter.

Citation

Beg, O., Basha, H., Sivaraj, R., & Prasad, V. (2021). Computation of non-similar flow of a magnetic pseudoplastic nanofluid over a circular cylinder with variable thermophysical properties and radiative flux. International Journal of Numerical Methods for Heat and Fluid Flow, 31(5), 1475-1519. https://doi.org/10.1108/HFF-04-2020-0236

• Journal Article Type: Article
• Acceptance Date: Jul 28, 2020
• Online Publication Date: Dec 18, 2020
• Publication Date: May 3, 2021
• Deposit Date: Jul 29, 2020
• Publicly Available Date: Jan 6, 2021
• Journal: International Journal of Numerical Methods for Heat & Fluid Flow
• Print ISSN: 0961-5539
• Publisher: Emerald
• Volume: 31
• Issue: 5
• Pages: 1475-1519
• DOI: https://doi.org/10.1108/HFF-04-2020-0236
• Publisher URL: https://doi.org/10.1108/HFF-04-2020-0236
• Related Public URLs: http://www.emeraldinsight.com/loi/hff