Double-diffusive transport and thermodynamic analysis of a magnetic microreactor with non-Newtonian biofuel flow

Abstract

Magnetic microfuel-reforming is a promising method of biofuel processing in diesel engines. However, the complex interactions amongst the non-Newtonian biofuel flow, magnetic field and reactor have hindered understanding of their influences upon the transport phenomena in the system. To resolve this issue, the transport of heat and mass in a porous microreactor containing a Casson rheological fluid and subject to a magnetic field is investigated analytically. The system is assumed to host a homogenous and uniformly distributed endothermic/exothermic chemical reaction. Two-dimensional analytical solutions are developed for the temperature and concentration fields as well as the Nusselt number and local entropy generations, and the results are rigorously validated. It is demonstrated that changes in the non-Newtonian characteristics of the fluid and altering the magnetic and thermal radiation properties can lead to bifurcation of temperature gradient on the surface of the porous medium. The general behaviour of such bifurcation is dominated by the exothermicity (or endothermicity) of the chemical reaction in the fluid phase. It is also shown that variations in the Casson fluid parameter and changes in the intensity and incident angle of the magnetic field can modify the Nusselt number considerably. The extent of these modifications is found to be heavily dependent upon the wall thickness and diminishes as the walls become thicker. Further, the total entropy generation is shown to be highly sensitive to the wall thickness and increases by intensifying the magnetic field, provided that the microreactor walls are thin.

Effects of heterogeneous catalysis in porous media on nanofluid-based reactions

“…They used the local thermal non-equilibrium method with two porous-fluid interface models to study the heat transfer in the porous section of the microreactor. At the same time, the heat and mass transfer in a porous microreactor with Casson fluid and inclined magnetic field were presented by Saeed et al [14,15]. Importantly, Alizadeh et al [16] depicted the forced convection of heat and mass on a cylindrical catalytic surface with non-uniform transpiration and impinging flow in porous media.…”

Upshot of heterogeneous catalysis in a nanofluid flow over a rotating disk with slip effects and Entropy optimization analysis

“…The impact of wall thickness on thermal performance has been considered. The exothermic catalytic process to examine the heat transfer phenomenon with an inclined magnetic field in the inner walls of porous microreactors is accomplished by Saeed et al 27 , 28 . Alizadeh et al 29 investigated forced convection in the presence of catalytic surface impinging stagnation flows embedded in porous media.…”

Entropy generation in Casson nanofluid flow over a surface with nonlinear thermal radiation and binary chemical reaction

“…There are some schemes that have been used to control the heat exchange 3 and the use of nanofluids. Entropy generation in the viscous fluid flow having copper nanoparticles was examined by Hayat et al 4 The double‐diffusive and thermal radiation upon transport in catalytic porous magnetic non‐Newtonian biofuel flow was established by Saeed et al 5,6 Alizadeh et al 7 analyzed the cylindrical surfaces with nonuniform porous media.…”