Abstract

The flow in pipes for non-Newtonian fluids is considered using a truncated series relating the shear stresses whit the radial velocity gradient. This approximation is used as an alternative way for the quantification of velocity profiles, and a lower order theoretical solution for the velocity is presented. It is observed that the calculated profiles allow approximations to pseudoplastic and to dilatant behaviors, approaching the Newtonian (parabolic) profile from the “inner side” or the “outer side”, respectively. This suggests that power series may be used to quantify aspects of non-Newtonian fluids. In the sequence, the possibility of turbulent flows in pipes was considered, and a qualitative view of the velocity profiles and the turbulent shear stresses is then presented here. This study was conducted theoretically, aiming the obtainance of solutions that allow verifying mathematical possibilities and impossibilities (such as discontinuities). The results suggest further numerical studies to evidence the possibilities of this kind of approximation.