Abstract:
In this work the hydrodynamic description of polymeric liquids is, for the first time, applied to different fundamental types of flow. By comparing the results with experimental findings, it is shown that this new theory is able to describe the basic flow properties of polymeric fluids very well.
At first the hydrodynamic model is strongly simplified and considered in the limit of small elastic strain. The resulting equations are used for discussing the flow behaviour in stationary and time-dependent shear and elongational flow geometries, in addition, surface deformation effects like the Weissenberg effect are considered.
Furthermore, a qualitative generalization is presented that allows the description of a flow with large elastic strain. This modification of the model is applied to different examples where interesting effects occur at larger strain. Finally, different empirical relations known from rheology are considered.
In addition, some scarcely considered non-Newtonian flow properties of ferrofluids in external magnetic fields are discussed by using the so called ferro-fluiddynamics. Some of the flow geometries considered for polymeric liquids are revisited and analysed for different magnetic field orientations. In addition, the results are compared to the properties of polymeric liquids.