Analysis of a Rotating Sphere in an Unsteady MHD Hybrid Nanofluid: A Theoretical and Computational Simulation Study with Hall Current and Joule Heating Effects

The study investigates the flow behaviour of an unsteady MagnetoHydroDynamic (MHD) hybrid nanofluid flow, influenced by Hall current and Joule heating with externally applied magnetic field imposed on the fluid flow model. This analysis also incorporates the thermophoretic velocity effect in the context of a revolving and stationary sphere. This research aims to shed light and provide essential insights into the thermodynamic interaction of these factors on heat transmission and fluid flow. A hybrid nanofluid (Ag-TiO 2 /H 2 O) over a rotating sphere with free stream velocity, u e is modelled that employs Tiwari-Das model for nanofluids. The indulged governing equations are non-dimensionalized to a complex, non-linear, unsteady differential equations, solved through Homotopy Analysis Method as its significance lies in its flexibility and controllability. The key findings convey that the Joule’s dissipation effects can significantly reduce the thermal boundary layer. Moreover, in the presence of a Hall current it causes a spike in the momentum boundary layer thickness approaching from the effect of the Hall potential difference. The temperature gradients considerably diminishes the thermal boundary layer’s thickness with increased values corresponding to thermophoretic parameter, τ , which greatly improves the diffusion mass transfer. Additionally, temperature profiles are raised due to better radiation parameter values. The present model explores the effect of Stanton number that particularly used in applications that require high efficient thermal management systems. The fluid flow has also been simulated to visualise the streamlines through computational simulations. The computational Nusselt number was found to be the greatest when percentage of volume fraction was at 0.01 at time, t = 0 seconds and the lowest when the NPs are at 0%.