FINITE-ELEMENT ANALYSIS OF TRANSIENT HEAT AND MASS TRANSFER IN MICROSTRUCTURAL BOUNDARY LAYER FLOWFROM A POROUS STRETCHING SHEET

In the present study, the unsteady laminar heat and mass transfer in incompressible micropolar boundary layer flow from a porous stretching sheet with variable suction has been examined. The unsteadiness in the flow, temperature, and concentration fields is caused by the time dependence of the stretching velocity, surface temperature, and surface concentration. By using a similarity transformation the governing time-dependent boundary layer equations with appropriate boundary conditions are rendered into a set of nonlinear ordinary differential equations. The dimensionless governing equations are then solved numerically by using the finite-element method. The effect of the suction parameter, unsteadiness parameter, coupling constant parameter, and Schmidt number on the distributions of the velocity, microrotation, temperature, and concentration functions are examined at length. The skin friction, wall heat transfer rate, and wall mass transfer are also computed. Under special cases, comparison of the flow velocity and rate of heat transfer is made with the exact solution and also with numerical results available from the literature. An excellent agreement between the results is obtained. Furthermore, validation of the present finite-element solutions is also achieved with a second-orderaccurate finite-difference method outlined in the literature. In addition, the convergence of the finite-element numerical solutions is discussed explicitly. The study is relevant to materials-processing technology.