The Effects of Newtonian heating and velocity ratio on entropy generationc in thermally dissipating flow above a thin needle

Abstract In this article, we investigated entropy generation analysis for viscous fluid over a thin needle. Two types of viscous fluids namely air and water are considered as counter examples. The energy dissipating term is included in the axial direction. The Newtonian heating condition is considered on the needle boundary. The governing equations for the flow under consideration are modeled in terms of partial differential equations (PDEs) which are then transformed into ordinary differential equations (ODEs) by using appropriate similarity variables. The transformed ODE's are then solved numerically using a numerical technique known as the Quasi-linearization method. The effects of embedded flow parameters on velocity, skin-friction, temperature, Nusselt number, Bejan number, and the irreversibility distribution ratio are determined graphically in several plots for both air and water. It is noticed that the total entropy generation N s t rate decreases with the increasing size of the thin needle. It is also found that the velocity ratio parameter e reduced the skin friction. It is worth noting that the needle size a and the Newtonian heating parameter γ reduced the irreversibility distribution ratio Φ .