Casson nanoliquid film flow over an unsteady moving surface with time-varying stretching velocity.

Present study explains about unsteady Casson nanoliquid film flow over a surface moving with velocity [Formula: see text]. The governing momentum equation is reduced to ODE by using corresponding similarity transformation, which is then tackled by employing numerical technique. The problem is analysed for both two-dimensional film flow and axisymmetric film flow. The exact solution is derived which satisfies the governing equation. It is noted that solution exists only for a specified scale of the moving surface parameter [Formula: see text]. ie., [Formula: see text] for two-dimensional flow and [Formula: see text] for axisymmetric flow. The velocity increases first and reaches the maximum velocity and then decreases to the boundary condition. Streamlines are also analysed for both axisymmetric and two-dimensional flow patterns by considering the stretching ([Formula: see text]) and shrinking wall conditions ([Formula: see text]). Study has been made for large values of wall moving parameter [Formula: see text]. The aim of this investigation is to analyse the Casson nanoliquid film flow which finds applications in industries like coating of sheet or wire, laboratories, painting, many more.