Non-Newtonian pressure drop and critical Reynolds number through rectangular duct

Results of an experimental study on non-Newtonian flow in rectangular duct are presented. The critical Reynolds numbers were measured using a flow visualization technique for flow of distilled water and CMC solutions as the working fluids. Also axial static pressure measurements in the different locations of the duct were made for Newtonian and purely viscous non-Newtonian fluids. Results indicate that as the pseudoplasticity of the solution increases the critical Reynolds number increases while the dimensionless pressure drop decreases. The results of pressure drop obtained by the present investigation are in very good agreement with available correlations in the literature. (C) 2001 Elsevier Science Ltd.