Drag-reducing agent

G. B. Eaton and M. J. Monahan. Composition of and process for forming polyalphaolefin drag reducing agents. Patent US 5869570, 1999. 

K. Fairchild, R. Tipton, J. F. Metier, and N. S. Kommareddi. Low viscosity, high concentration drag reducing agent and method therefor. Patent WO 9701582, 1997. 

N. S. Kommareddi and L. J. Rzeznik. Microencapsulated drag reducing agents. Patent US 6126872,2000. 

Hydrolysis increases the terpolymer limiting viscosity number in water by a factor of up to 45. Other previously published data(66-68) show that these terpolymers are nonnewtonian viscosifiers, metal-ion complexing agents, and effective flocculators. These materials are still "small" molecules in aqueous solution, however, and do not function as effectively when used 1. as nonnewtonian viscosifiers or 2. drag reducing agents as do poly(l-amidoethylene-co-(sodium 1-carboxylatoethylene)) copolymers. 

A drastic reduction of drag in the turbulent flow of solutions in comparison to the pure solvent can be observed, even when only minute amounts of suitable additives are added. This report shows that a wide range of technical and biochemical applications exists but that these applications have so far only been realized in a few exceptional cases. The reason for this must surely lie in the fact that a precise explanation for the effectiveness of drag reducing agents is neither possible from mathematical theories nor from molecular modelling. 

Smith JM, Bartels PV (1985) Influence of drag reducing agents on mixing in turbulent pipe flow Paper presented on the workshop Rheology of the professional commitee held in Bonn, Feb. 25... 

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