## THERMAL SCIENCE

International Scientific Journal

### Thermal Science - Online First

online first only
### Numerical investigation of magnetic nanofluids flow over rotating disk embedded in a porous medium

**ABSTRACT**

Combined effects of thermal radiation and variable viscosity on a time-dependent boundary layer flow (BLF) of magnetic nanofluids (MNF) over a rotating disk in the presence of the porous medium have been numerically investigated. To carry out the study, Hydrocarbon based magnetic nanofluid containing magnetite Fe3O4 particles of 10 nm with magnetic phase concentration of 10% has been taken. For numerical solutions of the modeled system containing the governing equation of the flow, a Matlab tool ODE45 is employed with shooting technique for the initial guess of the unknown boundary conditions. The flow phenomenon and heat transfer on the plate surface are characterised by various flow parameters such as viscosity variations, unsteady rotation parameter, Prandtl number and radiation parameter. Also, a comparative thermal analysis has been carried out for MNF having three different bases viz. hydrocarbon, fluorocarbon and water. Results reveal that heat transfer rate of hydrocarbon base MNF is 73.4511% faster than water base MNF and 239.7458% faster than fluorocarbon base MNF. This enhanced heat transfer capacity of hydrocarbon base MNF will help in improving the performance of oil and ore extraction drilling systems used in mining industry and other geothermal applications.

**KEYWORDS**

PAPER SUBMITTED: 2017-03-23

PAPER REVISED: 1970-01-01

PAPER ACCEPTED: 2017-05-23

PUBLISHED ONLINE: 2017-06-04

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