HEAT TRANSFER IN UNSTEADY MAGNETOHYDRODYNAMIC FLOW OF FOURTH-GRADE FLUID THROUGH A POROUS MEDIUM BETWEEN TWO INFINITE PARALLEL PLATES WITH TIME DEPENDENT SUCTION

摘要

A numerical investigation is carried out to study the unsteady flow of incompressible and electrically conducting fourth-grade fluid through a porous medium between two infinite parallel plates under transverse magnetic field with time-dependent suction. The lower plate is at rest and the upper plate is moving and oscillating in its own plane about a constant mean velocity with time-dependent suction. The basic equations governing the flow and heat transfer are reduced to a set of non-linear partial differential equations. The governing equations are simplified using perturbation method with respect to time and the resulting sixth-order non-linear differential equations are solved numerically using Runge-Kutta method in association with the multi-shooting technique. The simulation results for velocity, temperature, skin friction, and the Nusselt number are discussed using pertinent flow parameters. The investigation reveals that the higher-grade fluid parameters influence significantly the fluid temperature. Moreover, comparison with previous studies shows good agreement as a special case of the problem.