Unsteady free convection heat and mass transfer in a walters b viscoelastic flow with radiaction past a vertical plate

Abstract

Flow of fluids bounded by one or two planes aroused the dragging interest of newlinethe mathematicians and provoked extensive study in the literature. The flow of fluids newlinebounded by one or two vertical planes is particularly important in the area of heat newlinetransfer in which flows through such geometries are explored by several authors. The newlineunsteadiness in the flow field is caused either by time dependent motion of the newlineexternal stream (or the surface of the body) or by impulsive motion of the external newlinestream (or the body surface). When the fluid motion over a body is created newlineimpulsively, the inviscid flow over the body is developed instantaneously but the newlineviscous layer near the body is developed slowly and it becomes fully developed newlinesteady state viscous flow after certain instant of time. The Walters-B viscoelastic newlinemodel was developed to simulate viscous fluids possessing short memory elastic newlineeffects and can simulate accurately many complex polymeric, biotechnological and newlinetribiological fluids. newlineA representative set of numerical results is shown graphically to illustrate the newlineinfluence of physical parameters viz., Radiation parameter and#1050408; = 0.5, viscoelastic newlineparameter and#915; = 0.005, Buoyancy ratio parameter and#1050416; = 1.0, Prandtl number and#1050418;and#1050446; = 0.71 newline(air), Schmidt number and#1050421;and#1050431; = 0.25 (Helium diffusing in the viscoelastic fluid), newlinethermal Grashof number and#1050409;and#1050446; = 0.1, mass Grashof number and#1050409;and#1050441; = 0.1, exponent in newlinepower law variation of the wall temperature and#1050441;, exponent in power law variation of newlinethe wall concentration and#1050442; on velocity and#1050424;, temperature and#1050422;, concentration and#1050405;, skin-friction newlineand#1050604;and#1051627; , Nusselt number and#1050416;and#1050449;and#1051627; and Sherwood number and#1050421;and#8462;and#1051627; . The Walters-B viscoelastic newlinemodel has been employed which is valid for short memory polymeric fluids. The newlinedimensionless governing equations are solved by an implicit finite difference method newlineiv newlineof Crank-Nicolson type. A systematic study on the effects of various parameters on newlinefluid flow heat and mass transfer characteristics is carried out. newlineIncreasing in the viscoelasticity reduces concentration. The time require