Approximate Analytical Study of Thin Film Flow of Third Grade Fluid And Entropy Generation In Pipe

in this study on thin film flow of third grade fluid and entropy generation in pipe ,the coupled non-linear ordinary differential equations are solved using perturbation technique. Effects of third grade fluid, magnetic field and Brinkman number on entropy generation number due to heat transfer and fluid friction is investigated. It is observed that increase in the third grade parameter increases entropy generation number more at the region close to the centre of the pipe and less towards the wall of the cylindrical pipe. Influence of magnetic field shows that it has the tendency of enhancing thermodynamic irreversibility which can lead to increased entropy generation.It is further observed that the Brinkman number which is related to the irreversibility of the fluid flow and heat transfer processes increases with fluid viscosity resulting in entropy generation increase, enhances viscous dissipation as such leads to an increase in entropy generation number. However, third grade parameter increases the fluid friction which can lead to a decrease in heat transfer irreversibility resulting in lower Bejan number.