Drag-Reduction Measurements for Three Polymers at 4°C

Abstract

Pressure-drop measurements were made for dilute solutions of three high-molecular-weight polymers in a miniature pipe-flow apparatus. The test section was 0.023 inch in diameter and could operate at Reynolds numbers from 1,000 to 7,000, so that both laminar and turbulent flow as well as the transition region were investigated.

The results obtained with Polyox WSR 301 at 4° were nearly identical with those previously obtained at room temperature and at 37°C. Drag reductions ranged from 20% for a 0.5-ppm solution at a Reynolds number of 3,700 to 58% for an 8-ppm solution at a 6,700 Reynolds number.

At 4°C a polyacrylamide (Separan AP-30) gave results similar to Polyox, except that approximately four times as much polymer was required to produce the same percent drag reduction.

The Guar gum curves had a different shape from those of the other two polymers, and required from 10 to 40 times as much polymer as Polyox to give the same drag reduction.

The different-shaped curve is probably the result of greatly diminished mechanical degradation with Guar gum, while the higher concentration requirement is attributable to its lower molecular weight.