Experimental Study of Drag Reduction by aqueous Polyacrylamide Solution

The addition of small amounts of soluble high molecular weight polymers to wall bounded flows is known to reduce the turbulent drag. The reduction of frictional drag in turbulent flow has been an active research field in recent years. This paper researches the drag-reducing characteristics of aqueous polyacrylamide solution in a closed circulation loop. The experimental results indicate that drag-reducing effect improves with high concentration of solution at 10℃ and drag-reducing effect decreases with high temperature of solution at 200wppm. This phenomenon is due to aqueous polyacrylamide solution weak ability to withstand mechanical shear and high temperature. The percentage of drag reduction of 200wppm aqueous polyacrylamide solution can be up to 65% at 10℃ and 50% at 20℃. In a wide range of applications of high molecular weight polymers drag reduction is promising for reasons of economy and/or performance in the future.