Investigation of the Cooling Jets Used in the Blown Film Process
Bibliographic record
Abstract
Abstract Measurements were performed to characterize the development of the cooling jets produced by a typical dual-lip air ring used in the blown film manufacturing process. The distribution of the pressure on the bubble surface and the velocity field in the region above the forming cone were measured for a rigid model bubble with a blow-up ratio of 2.5. The measurements indicated that the development of the flow below the top of the forming cone in the air ring could be divided into two regions separated by local maxima in the static and fluctuating pressure. These maxima seemed to be associated with the location where the lower jet attached to the bubble surface. There was a region of negative gauge pressure on the bubble surface below the forming cone that should act to stabilize the bubble against the forming cone in practical applications. Above the forming cone, the lower jet was initially decelerated and then entrained into the upper jet. The upper jet then attached to the bubble surface and finally the flow recovered to a wall jet along the bubble surface. The profiles of the static and fluctuating pressure in the first and third regions above the forming cone collapsed reasonably well when they were scaled using the velocity of the lower jet and the velocity of the upper jet, respectively. The magnitude of the local maxima in the static and fluctuating pressure where the upper jet attached to the bubble depended on the upper jet velocity and the ratio of the upper and lower jet velocities.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".