Heat and mass transfer analysis for MHD flow of nanofluid inconvergent/divergent channels with stretchable walls using Buongiorno's model

摘要

The present article investigates the flow, heat, and mass transfer in the convergent and divergent channels under the influence of magnetic field. The walls of the channel are also considered to be stretching/shrinking. Buongiorno's model is used to formulate the problem for nanofluids. The equations governing the flow are transformed to a set of nonlinear ordinary differential equations by employing appropriate similarity transformations. Solution of the equations is obtained with the help of a useful and efficient numerical technique called the Runge-Kutta-Fehlberg method. Influence of the various emerging parameters on velocity, temperature and concentration profiles is described pictorially. Comprehensive discussions on the results obtained are provided. Backflow phenomena are observed for the stretching of divergent channel when angle opening and Re are increasing. This backflow can be controlled in two ways: one is by applying a strong magnetic field and other by shrinking the walls of the divergent channels. These results can be useful in various practical situations. Furthermore, expressions for skin friction coefficient, Nusselt and Sherwood numbers are obtained, and the variations in these quantities are analyzed graphically. Comparison of the results obtained here with the ones already existed in the literature confirms our solutions.