Flow due to an infinite flat plate suddenly set into motion in a viscoelastic fluid: first Stokes problem

Abstract

The problem of flow and heat transfer due to an infinite flat surface suddenly set into motion in an unbounded mass of viscoelastic fluid is investigated under the consideration of time-dependent temperature distribution along the plate surface. A new type of similarity solution is devised that converts the governing partial differential equations into a set of non-linear ordinary differential equations with four physical parameters, viz., viscoelastic parameter k, unsteadiness parameter b, Eckert number E and Prandtl number Pr. These equations are then solved numerically by finite-difference method after using the perturbation technique owing to the inherent unavailability of the necessary boundary conditions for solving this type of flow problem. The influences of these parameters on this flow dynamics are graphically analysed. The present analysis discloses that both the velocity and temperature at a given location decrease with the increase of the elasticity in the fluid as well as the unsteadiness of the flow field. The analysis reveals that the elastic property of the fluids causes the back-flow inside the boundary layer after a certain value of the unsteadiness parameter depending upon the presence of elasticity in the fluids. Another important result of this study that comes from the heat transfer analysis is that the elasticity of the fluids reduces the severity of the unwanted effect of the viscous heating.