摘要
The purpose of this work is to investigate experimentally the pressure drop of drag-reducing polymer solutions in the fully developed flow region in a periodically sudden converging-diverging tube as well as in a straight tube.Testing fluids were aqueous polyacrylamide solutions with concentration ranged from 200 to 1400 w.p.p.m.,and the Reynolds number ranged from 5 x 103 to 7 x 104.Drag-reducing phenomenon is found to exist in the straight tube flow with the viscoelastic fluid,while in the periodically sudden converging-diverging tube the friction factor is insensitive to the concentration of solution
