Stagnation-point flow of an aqueous titania-copper hybrid nanofluid toward a wavy cylinder
International Journal of Numerical Methods for Heat & Fluid Flow
ISSN: 0961-5539
Article publication date: 24 August 2018
Issue publication date: 25 September 2018
Abstract
Purpose
The purpose of this paper is to investigate analytically the steady general three-dimensional stagnation-point flow of an aqueous titania-copper hybrid nanofluid past a circular cylinder that has a sinusoidal radius variation.
Design/methodology/approach
First, the analytic modeling of hybrid nanofluid is presented, and using appropriate similarity variables, the governing equations are transformed into nonlinear ordinary differential equations in the dimensionless stream function, which is solved by the well-known function bvp4c from MATLAB.
Findings
The current solution demonstrates good agreement with those of the previously published studies in the special cases of regular fluid and nanofluids. Graphical results are presented to investigate the influences of the titania and copper nanoparticle volume fractions and also the nodal/saddle indicative parameter on flow and heat transfer characteristics. Here, the thermal characteristics of hybrid nanofluid are found to be higher in comparison to the base fluid and fluid containing single nanoparticles. An important point to note is that the developed model can be used with great confidence to study the flow and heat transfer of hybrid nanofluids.
Originality/value
Analytic modeling of hybrid nanofluid is the important originality of present study. Hybrid nanofluids are potential fluids that offer better heat transfer performance and thermophysical properties than convectional heat transfer fluids (oil, water and ethylene glycol) and nanofluids with single nanoparticles. In this investigation, titania (TiO2, 50 nm), copper (Cu, 20 nm) and the hybrid of these two are separately dispersed into the water as the base fluid and analyzed.
Keywords
Acknowledgements
The authors wish to thank the reviewers for their careful, unbiased and constructive suggestions, which led to this revised manuscript.
Citation
Yousefi, M., Dinarvand, S., Eftekhari Yazdi, M. and Pop, I. (2018), "Stagnation-point flow of an aqueous titania-copper hybrid nanofluid toward a wavy cylinder", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 28 No. 7, pp. 1716-1735. https://doi.org/10.1108/HFF-01-2018-0009
Publisher
:Emerald Publishing Limited
Copyright © 2018, Emerald Publishing Limited