Title screen

[References: p. 42 (23 tit.)]

The physicochemical concept of turbulent drag reduction (the Toms effect) integrates physicochemical characteristics of polymer solutions with hydrodynamic and rheological flow parameters into a generalized equation, where the increment in volumetric flow rate QP is a function of the external shear stress ?w, temperature, volume of macromolecular coils with immobilized solvent Vc and a function of their volume fraction ? = C · [?]/(1 + C · [?]). The QP depends on the coil intrinsic elasticity [G] = kT/Vc as well. This model allows one: (1) to describe the Toms effect in terms of useful elastic work spent by macromolecular coils with immobilized solvent to overcome the frictional forces (i.e. the forces of intermolecular interactions), (2) to forecast the initial conditions of the Toms effect (?* ? (RT)/(M · [?])) and (3) to explain the unusual temperature dependence of the polymer solutions flow.