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 vis ualization technique for flow of distilled water and CMC solutions as the w orking fluids. Also axial static pressure measurements in the different loc ations of the duct were made for Newtonian and purely viscous non-Newtonian fluids. Results indicate that as the pseudoplasticity of the solution incr eases the critical Reynolds number increases while the dimensionless pressu re drop decreases. The results of pressure drop obtained by the present inv estigation are in very good agreement with available correlations in the li terature. (C) 2001 Elsevier Science Ltd.