Numerical simulations of polymer flow in flat spiral dies
Bibliographic record
Abstract
Abstract The flow of a polymer melt through a flat spiral distribution system used in “stacked” type dies was analyzed through three‐dimensional finite element simulations, and predictions of the exit flow variation were compared to experimental measurements. Both isothermal and non‐isothermal simulations were carried out, and the non‐isothermal results were found to be in close agreement with the measured flow variation. It was found that for this particular flat spiral die, viscous dissipation is extremely crucial and may lead to generation of hot spots and to increased flow variation. Finally, the effect of material viscoelasticity on the flow field was simulated by using a CEF constitutive equation. It was shown that neglecting viscoelastic effects due to shear deformation, represented by primary and secondary normal stress coefficients, in the modeling of the flow in the flat spiral dies is a reasonable simplification. On the other hand, extensional behavior should be taken into account for a more suitable description of the leakage flows within this type of die.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".