Air demand in plunging dropshafts of medium height
Bibliographic record
Abstract
Falling water in dropshafts can induce a significant amount of airflow into sewer systems. In this study, the air demand in plunging-type dropshafts with medium drops of 3.38 and 1.88 m were investigated. The downward movement of air in the dropshaft is influenced by two components of falling water: the annular flow attached to the shaft wall and the bounced flow (in the forms of mainstream or water droplets). A model for predicting air pressure gradients was developed and experimentally validated. The air demand increased with the air inlet area, the drop height, the water flow rate, and the ratio of the bounced jet to the total water flow rate. A prediction model for the air demand in dropshafts was developed, thus it is possible to assess the air demand of dropshafts across a range of drop heights, diameters, and inflow conditions. When the air inlet to the shaft is restricted, a large negative pressure is generated inside the shaft, increasing the height of the water-air mixture generated by the bottom jet impact, which reduces the impact pressure at the bottom.
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".