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 of magnetic nanofluids 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 Fe 3 O 4 particles of 10 nm with magnetic phase concentration of 10% has been taken. For numerical solutions of the modelled 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 magnetic nanofluids having three different bases viz. hydrocarbon, fluorocarbon, and water. Results reveal that heat transfer rate of hydrocarbon base magnetic nanofluids is 73.4511% faster than water base magnetic nanofluids, and 239.7458% faster than fluorocarbon base magnetic nanofluids. This enhanced heat transfer capacity of hydrocarbon base magnetic nanofluids will help in improving the performance of oil and ore extraction drilling systems used in mining industry and other geothermal applications.

FHD flow and heat transfer over a porous rotating disk accounting for Coriolis force along with viscous dissipation and thermal radiation

“…The validation of the findings adopted in the present study is shown in Table 2 by comparing the heat transfer rate with the published work by Joshi et al, 26 Maleque 49 and Sparrow and Gregg; 48 who studied the similar problems for the case of laminar flow of viscous incompressible magnetic nanofluid over the rotating disk. The comparison manifests outstanding agreement, and hence encouragement for Maple environment in the present study.…”

“…Moreover, the linearized magnetic equation of state, boundary layer approximation in the radial direction, and magnetic potential with magnetic dipole (m) are described as reported by the authors. 26,43 Furthermore, the flux induced by thermal radiation [45][46][47] (Rosseland estimation for the radiation) can be popularized as follows:…”

“…Further, the variation in the magnetic field is assumed as negligible in the z ‐direction. Moreover, the linearized magnetic equation of state, boundary layer approximation in the radial direction, and magnetic potential with magnetic dipole ( m ) are described as reported by the authors 26,43 . Furthermore, the flux induced by thermal radiation 45–47 (Rosseland estimation for the radiation) can be popularized as follows: $$${q}_{r}=-\frac{4\sigma }{3{k}^{* }}\frac{\partial {T}^{4}}{\partial z},$$$ where $${k}^{* }$$ and $$\sigma \,$$ represent the mean absorption coefficient and the Stefan‐Boltzmann constant, respectively.…”

“…Hayat et al 25 described the magnetohydrodynamic (MHD) flow of copper–water nanofluid, considering the thermal radiation effect. Recently, Joshi et al 26 discussed variable viscosity effects along with thermal radiation on the time‐dependent flow of magnetic nanofluid. Moreover, Archana et al 27 analyzed the flow of Casson nanofluid and noted the fact that the thermal resistance gets hiked for growing in the radiation parameter.…”

Hydromagnetic boundary layer flow with heat transfer past a rotating disc embedded in a porous medium

“…Turkyilmazoglu 23 focused on water‐based nanofluids and elaborated the impact of nanoparticles on heat transfer and flow pattern with a rotating disc. Moreover, Griffiths, 24 Ram et al, 25 Joshi et al, 26 and Bhandari and Husain 27 also worked on the problem related to the rotating disc.…”