Fluid structure interaction - A study of pouring, using FSI-simulations

Abstract: At Tetra Pak the liquid packages are constantly developed and refined to fill the customer’s needs. A powerful tool is simulation, to evaluate the design of a new package early in the development process. To determine the performance of beverage packages at Tetra Pak different tests are made in different ways to make secure that they meet the requirements. The pouring performance of a package is a critical parameter, which needs to be considered when developing a new package. In this master’s thesis the pouring case will be considered. The goal is to evaluate the possibilities to perform FSI-, Fluid Structure Interaction, simulations of the dynamic pouring case and develop a simulation strategy for these kinds of simulations. In future Tetra Pak wants to be able to simulate “real” packages to better understand the pouring behaviour. This model can then be used to better understand dynamics, of pouring and make predicting about future packages for various products in a virtual pouring rig. The FSI-simulations has been performed in the computer software ANSYS Inc. 14.0.0 WorkBench, since this version of ANSYS has the capability of performing strongly coupled FSI- simulation, due to the boundary source coefficient that has been developed. The development of the pouring methodology has been performed on a small conceptual package with a small opening. This work is a continuation of the proof of concept developed by Tobias Berg from ANSYS in Gothenburg. The thesis includes test of the time step, the gulping dynamics, the boundary source coefficient, VOF scheme, Young’s modulus, density, effect of the surface tension and a scale up of volume. Table 1 shows a summary of all the tests that have been made for frequency and the amplitude that were given for the tests, from the deformation in Z-direction. The Young’s modulus is a factor of x'108 Pa.