Localised prediction accuracies of knowledge-guided symbolic regression models for melt conveying in single-screw extruders

Excel spreadsheet with numeric values and textual description.Contains the mean absolute errors (MAE) of symbolic regression models for predicting the dimensionless melt flow rate in single-screw extruders, averaged across all repetitive runs and distinct sub-regions for the dimensionless down-channel pressure gradient Pi_p and the power-law index n of the polymer melt.

The models were created from numerical simulation data with four different cases of integrated domain knowledge:

Case 1: theory of similarity only,

Case 2: additional derived input features for pure pressure flow,

Case 3: logarithmic scaling of the dimensionless flow rate with channel aspect ratio as derived input feature,

Case 4: theoretical approximation equation for superimposed drag and pressure flow in dimensionless space.