The steady two-dimensional flow of an incompressible non-Newtonian Molybdenum Disulfide nanofluid in the presence of source or sink between two stretchable or shrinkable walls under the influence of thermal radiation is investigated numerically. A generalized transformation is applied to convert the constructed set of partial differential equations (PDEs) into the system of non-linear coupled ordinary differential equations (ODEs). The obtained system of ODEs are solved by using Runge-Kutta 4th and 5th order. The influence of physical parameters, shrinking/ stretching parameter, Casson parameter, Hartmann number, Reynolds number, solid volume fraction, opening angle of the channel and radiation parameter on the velocity and temperature distribution are observed for converging and diverging channels. It is noticed that thermal boundary layer thickness is diminished for increased thermal radiation resulting in gradual temperature fall. The results also reveal that velocity and temperature profile both are elevated on raising the stretching parameter and Hartmann number. A comparative analysis is made out to validate the present results.

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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.

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