Polymer-induced drag reduction in turbulent flow is bounded by a universal upper limit with increasing fluid elasticity. For decades, efforts to understand this maximum asymptote have focused on the search for an ultimate state whose dynamics no longer influenced polymer Contrary common assumption, study shows that behind converged mean flow, underlying continues evolve through distinct stages,...

Two distinct scaling procedures were found to predict the diameter effect for different types of drag-reducing fluids. The first one, which correlates the relative drag reduction (DR) with flow bulk velocity (V), appears applicable to fluids that comply with the 3-layers velocity profile model. This model has been applied to many polymer solutions; but the drag reduction versus V scaling proced...