Flow Uniformity Characterization and Its Application in Extruder Flow Channel Design Optimization

We are interested in developing a general design optimization loop for extruder flow channel inserts based on 3-D finite element analysis (FEA). A key step of the computational procedure is the automated flow uniformity assessment which requires a quantitative characterization of the flow uniformity at the exit opening. To this end, a non-dimensional flow uniformity parameter is proposed, which is independent of flow rate & geometric dimensions and applicable to any shape of the flow channel cross-section. For a rectangular exit opening, two additional flow uniformity parameters are used to characterize the flow distribution in the two principal directions of the exit cross-section. The proposed flow uniformity parameter was successfully used as the objective function in an automated optimization loop for geometric design of flow channel inserts. The automated optimization loop allowed us to explore the design space in a broad range. Simulation results show that flow balance is consistently improved with the expansion of the design search space. It was also found that the automated optimization loop provides a better optimal solution than those obtained from the manual optimization approach under the same pressure-drop constraint.