Measurement of drag reduction in polymer added turbulent flow

In this study, polyethylene oxides were used as a drag reducing additive. The effect of the concentration and molecular weight of the polymer on the level of drag reduction was examined using, 4 molecular weights (2 × 105, 4 × 105, 9 × 105 and, 4 × 106) and 4 concentrations (1, 5, 10 and, 20 wppm) of PEO. The hydraulic conditions were varied from a Reynolds number of 30,000 to 60,000. The results showed a > 20% drag reduction rate for all molecular weights and constructions of PEO within the range investigated in this study. Moreover, the maximum drag reduction rate was 50% at a molecular weight and concentration of 4 × 106 and 20 wppm, respectively. Overall, the results show that the drag reduction effect tends to increase with increasing molecular weight and Reynolds number.