REVIEW OF REOLOGICAL MODELS

Abstract

Foodstuffs during harvesting, transportation, storage, especially during processing are subject to various mechanical influences. In this case, the production processes should be organized in such a way as to ensure the highest possible level of quality of finished products. A successful solution to this problem is the knowledge of rheological properties and texture of food products. Food products, including raw materials and semi-finished products, vary by their composition, disperse composition and structure, with different rheological properties with texture distinctive features. 

The article analyzes both elementary rheological models such as the model of Hooke (perfectly elastic body), Newton (perfectly viscous body) and Saint-Venant – Coulomb (ideally plastic body) as well as other more complex combinations of these elementary rheological models such as as the model of Maxwell, Kelvin –Voigt, Ziner, Prandtl, Bingham and others. Examples of their use are also given. 

Biological agricultural materials have a complex multilayered rheological structure. Preferably, each of these layers has its own, different from other properties. Therefore, for a more precise description of the behavior of biological agricultural materials during transportation, and the process of processing, and in particular in the interaction with the working bodies of cars, it is necessary to study in detail the rheological structure of these materials. 

In order to adequately describe the rheological properties of agricultural materials, it is necessary to use models consisting of three or more elements. However, with increasing number of elements, not only the precision of the description of a particular biological material increases, but also their mathematical analysis becomes much more complicated.