CFD Parametric screening of a filling machine

L. Bucchieri, M. Galbiati (Enginsoft), R.Borsari (Tetra Pak)

TetraPak Carton Ambient has the need to investigate the behavior of the fluid dynamic filling process of their typical product: 1 liter carton filled with foodstuffs (milk, juices, etc.).
Scenarios to be investigated are machines operating at different production speeds (low to high number of liters/packs per hour) with different pressure damping systems. This study analyzes particular positions of the machine in order to evaluate if the pressure is too high or too low.

CFD calculation set up:
–cylindrical coordinates for simplicity of mesh movement
–multiphase flow for free-surface calculation
–transient flow simulation
–Solver option -CFX
–Moving -Deforming Transient Mesh
–Turbulent flow
–AMG solver for robust convergence
–200 time steps

The SOBOL Design Of Experiment run by modeFRONTIER is an uniform distributed screening out of which it is easy using statistical correlation to find the assessment between input and output variables.
Significance to the output variables has been found for the following inputs:
– Hole diameter
– Head
– Production speed
Non-significance has been found for the following inputs:
– Flange diameter
– Viscosity and density (In the considered range of values !)

It has been found that given a particular production speed we can obtain a desired overpressure (but not too high) with a tuning of the head and the hole diameter. Hence in a production scenario in order not too have excessive distortion of the carton boxes different flanges can be assembled on the machine with an adequate head in order to have smooth production, hence the damping system can be designed and calculated via CFD.