Buoyancy effects on nanofluid flow past a convectively heated vertical Riga-plate: A numerical study

The main concern here is to study nanofluid flow past a vertical Riga-plate subjected to convective heating. Riga-plate is composed of span wise aligned array of electrodes and permanent magnets fixed on a plane surface. This arrangement induces Lorentz force parallel to the array which decays exponentially with distance normal to the plate. Practically useful assumption of zero normal wall mass flux is imposed. Traditional transformations give rise to the locally similar equations which are treated numerically by shooting approach. MATLAB built-in package bvp4c, based on collocation method, is also implemented for generating numerical results. Results show that velocity distribution parallel to the plate is enhanced due to the inclusion of Lorentz force. Drag reduction is anticipated in the case of opposing flow, which is important in engineering applications. Temperature and wall heat flux are increasing functions of convective heating parameter (Biot number). For assisting flow regime, temperature drops when either the wall-parallel Lorentz force or buoyancy forces become stronger. Heat flux from the plate is not affected, with the variation in Brownian diffusion coefficient. Moreover, highest heat transfer rate is achieved for the situation in which thermophoretic effect is absent. (C) 2017 Elsevier Ltd. All rights reserved.