Drag reduction in dilute polymer solutions

The problem of drag reduction in a helically coiled tube is examined experimentally. The general problems involved in the correlation of drag reduction data are analyzed critically, and some important recommendations are made based on the findings of this work. A phenomenological approach is suggested for correlating the drag reduction data. An examination of the straight-tube data from the literature and the coiledtube data obtained in this work shows that for a variety of aqueous polymer solutions the data could be uniquely correlated by the following equation: β= 0.2+0.8/1+(De') 0.8 where β = reduced friction factor and De' = modified Deborah number.