Unsteady mixed convection over an exponentially decreasing external flow velocity

A very recent study of Patil et al. (2017) on the effects of steady mixed convection flow with an exponentially decreasing free stream velocity motivates this research investigation. The present analysis reveals the mixed convection impact over an exponentially decreasing free stream velocity in an unsteady incompressible laminar boundary layer flow involving the effects of suction or blowing and heat generation or absorption. By utilizing the appropriate non-similar transformations, the complex dimensional governing boundary layer equations are simplified into dimensionless equations. In order to prevail the mathematical convolutions in attaining the non-similar solutions at the leading edge of the streamwise coordinate as well as non-similarity variable ξ, the coalition of implicit finite difference scheme and the Quasi-linearization technique is used with the suitable step sizes along the streamwise and time directions. The effects of various dimensionless physical parameters over the momentum and thermal fields are examined. The range of the parameters studied in this analysis are taken as α(-0.5⩽α⩽1.0), ξ(0⩽ξ⩽1), τ(0⩽τ⩽1), ε(0.000001⩽ε⩽0.1), Ri(-3⩽Ri⩽10), Re(10⩽Re⩽250), A(-1⩽A⩽1) and Q(-1⩽Q⩽1). Further, the present numerical investigation is focussed towards unsteady flow and heat transfer characteristics.