A brief comparative study of gamma alumina–water and gamma alumina–EG nanofluids flow near a solid sphere

Abstract

Here we deliberate a new class of nano-materials with two different types of nanoparticles which immensely magnify the thermo-physical properties and thermal transport proficiency of nano-liquid. Prandtl number exhibits a primitive role in regulating thermal or momentum boundary layer regions. Therefore, keeping such comprehensive spectrum in view we contemplated MHD natural convection flow of steady, 2D, incompressible nanoliquids of gamma alumina–water and gamma alumina–EG towards a solid heated sphere. Viscosity is supposed to be temperature dependent. Governing non-linear PDEs are formed. To renovate the PDEs into system of ODEs a felicitous transformation has been employed. The converted non-linear equations are executed numerically via BVP4C. The numerical conclusions derived for velocity and thermal distributions are perceived through graphs for two different cases, effective Prandtl number and without effective Prandtl number. A careful consideration of preceding dissertation discloses that, the significance of an empirical based Prandtl number model on the boundary layer flow of gamma alumina–water and gamma alumina–EG on a solid sphere with temperature dependent viscosity is not examined yet. A comparison reveals that gamma alumina–EG offers better thermal transfer enhancement than gamma alumina–water. Entropy generation number Ns is the ratio of local volumetric entropy generation rate to the characteristic entropy generation rate. Entropy generation analysis is also perceived and the behavior of Gr number relative to entropy generation number Ns is also presented. A parametric analysis of the substantial parameters such as magnetic field parameter M, nanoparticle volume fraction parameter ω temperature parameter θr and Gr number are ascertained and representative set of numerical examination for thermal and velocity distributions are depicted graphically to present the influential features of the solutions.