Boundary stratum exploration of unsteady 3D MHD stagnation point flow of Al–Cu water nanofluid

Abstract

A theoretical analysis of unsteady, three-dimensional stagnation-point flow of Al–Cu nanoparticle suspended water based nanofluid is performed. The thermophysical properties of alloy nanoparticles like density, specific heat capacity and thermal conductivity are computed using appropriate formula. A micro-convection based model framed by Patel et al. [1] is used for predicting the thermal conductivity of nanofluid. The governing physical model is mathematically modeled into a set of non-linear parabolic partial differential equations and solved by a shooting technique. A parametric study is performed for a varied range of nanoparticle volume fraction, ratio of the velocity gradient, unsteadiness parameter and the magnetic parameter. Additionally, the importance of the different compositional characteristics of the alloy nanoparticles on the flow and the thermal field is also examined. It is observed that the Nusselt number increases as the unsteadiness parameter λ decreases and the ratio of the velocity gradient c increases in the nodal point region. A novel result of the analysis reveals that the highest skin friction is obtained for Al50Cu50 - water and the highest Nusselt number is obtained for Al90Cu10-water.