Bibliographic record
Abstract
Perforated plates are a popular architectural feature found on the outside faces of buildings. These plates are known to produce flow-induced noise when exposed to high winds. While this noise is generally broadband, for certain plate geometries, flow velocities, and angles of incidence, highly tonal noise is produced, the level of which can be much higher than that of the broadband noise. This is an irritant for inhabitants of the building and the surrounding area and may lead to costly retrofitting to eliminate the problem. Many studies can be found in the literature for flow over perforated plates at a parallel or perpendicular direction. However, the literature is very limited with regards to flow over perforated plates at oblique angles of incidence. For architectural applications, the direction of the wind is naturally unpredictable, so the effect of different angles of incidence is an important consideration. As a preliminary investigation, a simplified model of a perforated plate is used. The circular holes of a typical perforated plate are replaced by a series of long rectangular slats with an adjustable gap width between them. This simplified model is studied experimentally in a wind tunnel for various angles of incidence and flow velocities. The acoustic response is studied using microphone measurements, and flow visualization is done using particle image velocimetry. It is found that tonal noise is produced for angles of incidence of 5 to 30 degrees from parallel. The Strouhal number of these tones agrees well with those produced by a perforated plate. Outside of this range of angles, the noise is broadband. The flow visualization reveals that this tonal noise is caused by the periodic shedding and impingement of vortices on the downstream edge of the holes.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 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 | 0.000 | 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".