Unsteady MHD flow of a micropolar nanofluid through a dilating channel
in the presence of ohmic heating
Abstract
Heat transfer in a magnetohydrodynamic (MHD) micropolar fluid through a
squeezing channel in the presence of viscous dissipation and Joule
heating is studied. The analysis is carried out over different water
based nanofluids consisting of alumina (Al2O3), titania (TiO2), and
magnetite (Fe3O4) nanoparticles. A model with non-linear partial
differential equations is converted to a set of non-linear ordinary
differential equations by the aid of similarity transformations. The
resulting equationsare then numerically solved by Runge–Kutta (RK)
method with fourth order approximation followed by shooting method. A
comprehensive investigation describing the influences of the physical
parameters such as vortex viscosity parameter, ohmic heating parameter,
Hartmann number, squeezing parameter and solid volume fraction parameter
on the distributions of temperature, velocity and microrotationis are
graphically showed. In the absence of squeezing and expanding, it is
observed that both water and nanofluid experience same viscous drag.
Further, an increase in volume fraction lowers the microrotation, and
thereby causing an elevation in the temperature of titania–water
nanofluid. This is in contrast to the behaviour of the other nanofluids.