Unsteady casson fluid flow past a stretching sheet

Abstract

In the present study, an investigation on unsteady Casson fluid flow past a stretching sheet is reported. The fluid is initially considered to flow with a non-zero velocity. This non-zero velocity is of Crane-type (flow). At a particular instant of time, the fluid is subject to instantaneous stretching of the sheet and various physical conditions. This instant introduction of instantaneous stretching and physical conditions sets the initial steady fluid flow to unsteadiness. This unsteady fluid flow, with progress in time, becomes steady. The various physical conditions are Crane velocity, the sudden introduction of the Casson fluid, instantaneous stretching of the sheet, application of natural convection, quadratic free convection, suction, transverse magnetic field, and thermal radiation. The nature of the ow, time to reach the steady flow, final steady flow, and effect of different physical conditions are reported, discussed, and presented. The results of the fluid flow are obtained through numerical methods, namely, the Crank-Nicolson (implicit finite difference) method. The report gives a brief overview of the stability and convergence conditions for the same. newlineIn the present problem(s) the flow is assumed to be steady. At a given instant of time due to the introduction of different physical conditions unsteadiness sets in. This unsteadiness leads to different patterns in the fluid flow. These patterns are captured (computed) using the finite difference technique mentioned. Results and discussions with the aid of plots have been presented. newlineOur results show that an increase in the Casson parameter leads to a decrease in fluid flow magnitude (magnitude means the absolute numerical values) and an increase in local skin friction. After the application of sudden stretching of the sheet, the fluid flow with initial non-zero velocity achieves the steady-state flow within a shorter duration of time compared to fluid flow at rest before the application of sudden stretching of the sheet.