The Effects of Thermocapillarity on the Thin Film Flow of MHD UCM Fluid over an Unsteady Elastic Surface with Convective Boundary Conditions

The study of two-dimensional flow and heat transfer in a liquid film of MHD Upper Convective Maxwell (UCM) fluid over an unsteady elastic stretching sheet subject to velocity slip and convective boundary condition is presented. Thermocapillarity effects are considered. Using suitable similarity transformations, the momentum and thermal energy equations are converted to a set of coupled nonlinear ordinary differential equations. These equations are solved numerically using the Keller-Box method. The velocity and the temperature distributions are presented graphically for different values of the pertinent parameters. The effects of the unsteady parameter on the skin friction, the wall temperature gradient, and the film thickness are tabulated and analyzed. The thermocapillarity parameter has a decreasing effect on the temperature field and the local skin-friction coefficient.

Double Dispersion Effects on MHD Squeezing Flow of UCM Fluid through a Porous Medium

The objective of the current problem is to explore the impact of wall motion on flow, heat and species concentration of a UCM fluid in a magnetohydrodynamic Darcian channel. The flow is confined between two moving walls. The effects of the wall motion on the physical quantities for expanding and contracting cases are studied through non-dimensional numbers and variables. Numerical solutions for the highly nonlinear differential equations are obtained by reducing the governing PDE to ODE using well-established similarity variables. The variation of skin friction, Nusselt and Sherwood numbers has been investigated with the help of surface plots so that the influence of the squeezing number on the other non-dimensional parameters can be deeply understood. The results suggest that the squeezing channel intensifies the mass transfer and skin friction at the walls and it also increases the velocity, temperature and concentration of the fluid across the channel.