CHARACTERIZATION OF THE TRANSITION FROM THE LAMINAR TO THE TURBULENT-FLOW REGIME FOR THE NON-NEWTONIAN FLUIDS

The paper presents a calculation method for the generalized parameter of the flow stability for the fluids having an Ostwald de Waele and Bingham type rheological behaviour, as a measure of transition from the laminar to the turbulent now regime. The fact that the critical value of the generalized parameter for the flow stability is an unique criterion to evidentiate the transition, irrespective of the fluid rheological behaviour, is rendered evident. The method presented has a general character since it can be expanded to other rheological methods as well. when the flow characteristic mesures are known (flow-rate, average flow-rate, shear deformation rate and the volumetric flow-rate to pressure fall total relationship).