A wide variety of new industrially used or produced materials and products is expected to exhibit tailor-made flow properties of the final product and fulfil the requirements of desired final performance. Control of such properties usually depends on the knowledge of process variables as well as on the ability to measure and mathematically characterise meaningful flow properties information. Constitutive models represent one of the basic points for characterization of materials behaviour and consecutive description of flow for the given geometrical arrangements. The aim of the proposed project is:
- - to present a new phenomenological rheological model suitable for the description of a wide class of viscoelastic fluids that exhibit nonmonotonous dependence of viscosity on deformation characteristics, this model should be sufficiently flexible to respect local extremes (maximum, minimum) and Newtonian plateau including an intermediate one; a number of entry parameters will be minimised;
- - to modify and compare the suitability of the advanced differential constitutive equations in modelling of industrially important steady flows, this will be done through investigation of their fitting and determination of predictive capabilities for industrially common polymer melts under steady state shear and uniaxial extensional flows, which usually occur in combination at polymer processing;
- - validation of the theoretical conclusions through own data and data in the literature.
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