Nanoparticle migration effects on fully developed forced convection of TiO2–water nanofluid in a parallel plate microchannel--颗粒学报PARTICUOLOGY

Hedayati, F., & Domairry, G. (2016). Nanoparticle migration effects on fully developed forced convection of TiO2–water nanofluid in a parallel plate microchannel. Particuology, 24, 96-107. https://doi.org/10.1016/j.partic.2014.11.012

Nanoparticle migration effects on fully developed forced convection of TiO₂–water nanofluid in a parallel plate microchannel

F. Hedayati ^a *, G. Domairry ^b

a Young Researchers and Elite Club, Neyshabur Branch, Islamic Azad University, Neyshabur, Iran
b Mechanical Engineering Department, Babol University of Technology, Babol, Iran

10.1016/j.partic.2014.11.012

Volume 24, February 2016, Pages 96-107

Received 9 September 2014, Revised 4 November 2014, Accepted 9 November 2014, Available online 7 April 2015, Version of Record 21 January 2016.

E-mail: hedayati.faraz@live.com

Highlights

• Slip velocity at the walls of microchannel was considered.

• Effect of asymmetric thermal boundary condition on particle distribution was studied in detail.

• Effects of thermophoresis and Brownian forces on the nanofluid flow in microchannel were analyzed.

• Effects of concentration, velocity, temperature on pressure drop and heat transfer were discussed.

Abstract

This study considers the forced convection of laminar TiO₂–water nanofluid flow in a parallel plate microchannel. The small length scale associated with microchannels dictates the use of slip condition at the fluid–solid interface. The modified Buongiorno model was employed for the nanofluid to fully account for the effects of non-uniform viscosity and thermal conductivity. The partial differential equations associated with conservation laws were reduced to two-point ordinary boundary value differential equations before being numerically solved. Considering Brownian motion and thermophoresis, the effects of nanoparticle transport on concentration, velocity, and temperature profiles were analyzed for three different values of wall heat flux. To assess the efficiency of adding nanoparticles, the ratios of the pressure drop and the heat transfer coefficient of the nanofluid to that of the base fluid were studied in detail. From analyzing different heat flux ratios, one-sided heating was found to be most efficient at enhancing the heat transfer rate in the microchannel. Additionally, in the presence of the slip velocity, the increase in the value of the heat transfer coefficient for the nanofluid was smaller than that for the base fluid.

Graphical abstract

Keywords

Nanofluid; Microchannel; Nanoparticles migration; Slip velocity; Brownian motion; Thermophoresis

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