Drag Reduction in Polymer Solutions

As mentioned in the introduction, the effect manifests in a decrease of pressure loss over a fixed length of a straight pipe compared with a flow of Newtonian fluids through the same pipe section at the same Reynolds numbers for Reynolds numbers which are higher than a certain critical value. This fact is equivalent to a reduction of the friction factor due to the added polymers, see Fig. 1.2 & 1.3. In this gross flow behaviour of the friction factor the main characteristics of drag reducing flows by polymers can already be observed.