Resumo: |
Development of a robust code for prediction of three three-dimensional time time-dependent viscoelastic fluid flows with a large variety of differential and integral constitutive equations. For validation, an extensive experimental and numerical investigation of critical conditions for the onset of elastic instabilities in square sudden contractions will be carried out as a function of the Weissenberg number and contraction ratio using visualization and velocity field measurements by streakline photography, LDA and PIV, pressure drop measurements and extensive numerical calculations. The implementation of the deformation fields method into our finite finite-volume based code for computational rheology will allow time dependent calculations with viscoelastic integral type constitutive equations. Our code is general and solves three three-dimensional time time-dependent transport equations, but is restricted to some differential constitutive models. New differential models will also be incorporated into the code. |