Unsteady effects on mixed convection boundary layer flow from a permeable slender cylinder due to non-linearly power law stretching

An unsteady mixed convection boundary layer flow over a permeable non-linearly stretching vertical slender cylinder is considered to investigate the combined effects of buoyancy force and thermal diffusion in presence of surface mass transfer, where the slender cylinder is in line with the flow. The unsteadiness in the flow and temperature fields is caused by the continuously non-linearly stretching vertical slender cylinder. The governing boundary layer equations are transformed into a non-dimensional form by a group of non-similar transformations. The resulting system of coupled non-linear partial differential equations is solved by an implicit finite difference scheme in combination with the quasi-linearization technique. Numerical computations are performed to understand the physical situations of linear and non-linearly stretching surface for different values of parameters to display the velocity and temperature profiles graphically. The obtained results show that the buoyancy parameter λλ and the Prandtl number Pr enhance the skin friction coefficient and the local Nusselt number. It is also shown that the suction parameter A (>0) is to decrease the velocity and temperature profiles, but injection parameter A (<0) does the reverse. Results are compared with previously published work and are found to be in excellent agreement.

► Mixed convection flow over a non-linearly stretching vertical slender cylinder is considered.
► Computations are performed to understand the effects of linear and non-linearly stretching surface.
► Velocity profiles exhibit significant overshoot for low Prandtl number fluids.
► Non-linear stretching reduces the thickness of momentum and thermal boundary layers.
► Buoyancy force and Prandtl number enhance the skin friction and heat transfer rate at the wall.