Simulation and Analysis of Foods Fluid Dynamic Behaviour during Filling Processes

This research presents a model describing the behavior of fluids during aseptic filling processes. The aim of the study is to determine the influence of the most important variable, such as viscosity, on the performance of filling valve in aseptic beverage plants, mainly in terms of time required to perform the filling process. Consequently, this study is intended to explore the possibility to increase the accuracy of filling processes, modeled by the use of finite elements method (FEM). Numerical simulations were performed to investigate the laminar flow and rheological behavior of shear thinning and Newtonian fluids in 3-dimensional steady state and time-dependent configurations. The mass and momentum balance equations were solved with the finite element method using commercial software Comsol Multiphysics 3.2a. Simulations, carried out in different pressure conditions on a non Newtonian fluid like a low fat yogurt, showed that a laminar flow subsists during the filling process when the Reynolds number is less than about 600. A comparison between the theoretical prediction and outcomes of experiments performed in industrial laboratories has shown a good correspondence of the results provided.