Mixed convection boundary-layer flow of a nanofluid near stagnation-point on a vertical plate with effects of buoyancy assisting and opposing flows

Abstract

In this study, the steady laminar mixed convection boundary layer flow of a nanofluid near the stagnation-point on a vertical plate with prescribed surface temperature is investigated. Here, both assisting and opposing flows are considered and studied. Using appropriate transformations, the system of partial differential equations is transformed into an ordinary differential system of two equations, which is solved numerically by shooting method, coupled with Runge-Kutta scheme. Three different types of nanoparticles, namely copper Cu, alumina AlR2ROR3R and titania TiOR2R with water as the base fluid are considered. Numerical results are obtained for the skin-friction coefficient and Nusselt number as well as for the velocity and temperature profiles for some values ofthe governing parameters, namely, the nanoparticle volume fraction parameter and mixed convection parameter It is found that the highest rate of heat transfer occurs in the mixed convection with assisting flow while the lowest one occurs in the mixed convection with opposing flow. Moreover, the skin friction coefficient and the heat transfer rate at the surface are highest for copper-water nanofluid compared to the alumina-water and titania-water nanofluids. © Maxwell Scientific Organization, 2013.