A Local Thermal Non-Equilibrium Approach to an Electromagnetic Hybrid Nanofluid Flow in a Non-Parallel Riga Plate Channel

Abstract

The fluid flow in a non-parallel configuration exists in the electronic heat removal devices, microchannel heat sinks, and angled confusers/diffusers. The fluids in these applications are prone to flow separation and bifurcations. To deal with such type of problems, a novel idea of a converging or diverging type Riga plate channel is introduced in this study. The Riga plates are utilised to produce the cross-flow magnetic and electric fields which give rise to an exponentially decaying Lorentz force. Also, a porous matrix with variable permeability is considered to fill the Riga plate channel. The thermal equilibrium state between the hybrid nanofluid and porous media is ignored i.e., a local thermal non-equilibrium (LTNE) approach is adopted to model the energy balance equations. The dimension-free form of the guiding equations is tackled by using the Chebyshev pseudospectral quasi-linearization method. The heat transfer rate is respectively incremented by 21.42% and 63.12% in the converging and diverging flow regimes, with the inclusion of a Riga Sheet. The skin friction coefficient is depressed with modified Hartmann number (Ha*) and porosity (ε) for the converging/diverging flow regime. The LTNE state alters to the LTE with Nield number (Ni), thermal conductivity ratio (γ) and ε.