Multiple Exact Solutions of Radiative Micropolar Hybrid Nanofluid: Hiemenz Flow

Abstract

Even though micropolar models are widely employed for many applications and treated numerically, exact solutions still possibly exist, in particular, in boundary layer problems. This topic studies an extended micropolar model, that based on hybrid nanofluids that retains the original model as a special case. We investigate the stagnation point flow of a bidirectional surface under velocity slip and heat radiation effect whose boundary layer equations are reduced to similarity form for exact solutions. Wall mass flux, material parameter, velocity slip, nanoparticles concentration and heat radiation affecting the existence of unique or numerous solutions of fluid flow and heat transfer are analyzed. The critical points appearing for both the stretching and shrinking sheets are definitive in locating the existence of physical solutions. It is noted that the stretching/shrinking strength parameter has a vital role in delineating the existence of exact solutions. Also, the velocity slip strongly suppresses the stretching or shrinking velocity pushing the peak velocity close to the minimal. The boundary thickness in temperature profiles are highly affected by the nanoparticle concentrations, mass transpirations and heat radiation effect. Results for the non-dimensional linear and gyration velocities, heat transfer and the heat transfer gradient are investigated pictorially detailing the effect of state parameters characterizing the transport phenomenon.