Abstract: In this work,we treat thethermal development problem, for apseudoplasticfluid in asinglepipe. A fully developed flow is supposed at the pipe inlet, with an imposedtemperature at the surface inthe case of aheating andcooling. In addition, the effect ofviscous dissipationis considered. Finite difference method with an implicit scheme is used to solve the energy equation. The main objectiveof the workisto provide results, enabling to well understandthe effect of viscous dissipationassociated with that ofrheological behavior. For this, different values oftheBrinkman(Br) number characterizing theheat generation byviscousfriction, and therheological index(n)have been taken in heating situation as well as cooling. It has been found that the fluid shear-thinning (n↓) significantly reduces the dissipative effect, by reducing the friction between the fluid layers.

Keywords:Forced convection; thermaldevelopment; pseudoplasticfluid; viscous dissipation.