DIFFERENTIAL MODELS OF RHEOLOGICALLY NONSTATIONARY FLUIDS

An analysis has been made of basic differential models of rheologically nonstationary (viscoelastic) fl uids as well as of their development and interrelation. The considered models cover a rich variety of viscoelastic media: polymer solutions and melts, natural formations (glaciers), and others. Among these models, a key role is played by the Maxwell upper convection model: it provides a theoretical basis for experimental determination of the dynamic characteristics of viscoelastic fl uids and for development of new rheological models. It has been shown that to improve the reliability of results obtained with the aid of a complex rheological model, it is expedient to ensure a possibility of reducing it to the existing models and thus fi nding analytical solutions for a number of the simplest fl ows. Examples of use of the models in question when results of rheometric investigations are approximated and viscoelastic-fl uid fl ows are calculated have been given. Special emphasis has been placed on an analysis of the correspondence of the derived solutions to the physical essence of the described processes, and also of the correctness of interpretation of some results or others.
   
Author:  O. M. Sokovnin, N. V. Zagoskina, and S. N. Zagoskin
Keywords:  mathematical models, viscoelastic fl uids, determination of dynamic characteristics
Page:  528