Non-Newtonian ferrofluid flow over an unsteady contracting cylinder under the influence of aligned magnetic field

Abstract

In this paper the basic design of the study is comparison between the magnetohydrodynamic (MHD) flow and heat transfer of non-Newtonian (Sodium Alginate) base fluid with three ferroparticles, that is Cobalt ferrite (CoFe2O4), Manganese–Zinc ferrite (Mn−ZnFe2O4) and Nickel–Zinc ferrite (Ni−ZnFe2O4) over an unsteady contracting cylinder. In this inspection the aligned magnetic field effects are taken into consideration. The process of bringing the governing PDE's to the form of ODE's is achieved with the similarity transformations. At this point the changed over conditions are numerically understood by Runge-Kutta method of fourth order with shooting technique. The non-Newtonian behavior is discussed employing Casson model. By means of visual image we explain and interpret the behaviours of several emerging parameters on the velocity and temperature profiles. Calculation for the local skin friction coefficient and local Nusselt number are evaluated and examined for the deserving parameters. Also, it is seen that the alignment of magnetic field helps in advancing the velocity profile. Comparing the nanoparticles it is observed that CoFe2O4 nanoparticle is dominant over the other for the local skin friction values whereas Ni−ZnFe2O4 nanoparticle has higher rate of heat transfer.