Effect of roughness and trips on the drag of a circular cylinder at subcritical flow
Bibliographic record
Abstract
The aerodynamic impact of surface roughness and trips on a circular cylinder was investigated. Surface roughness was caused by textile sleeves of seven distinct fabrics varying in roughness. These sleeves were configured with one or two seams strategically positioned to influence the flow dynamics over a Reynolds number range of 4 × 1 0 4 ⩽ Re ⩽ 1 . 3 × 1 0 5 . Measurements of the aerodynamic drag, lift, unsteady flow, and mean flow field were made. It is shown that seam(s) can reduce cylinder drag across the Reynolds number range. The parameters influencing this reduction include the number, position, configuration of seams, and fabric roughness. For a single seam, drag reduction of up to 45% and an increase in vortex shedding frequency were observed, relative to a smooth cylinder. In the case of fabrics with two symmetrical seams about the cylinder stagnation point, a significant reduction in the critical Reynolds number occurred, accompanied by approximately 35% drag reduction across a broad range of Reynolds numbers. Furthermore, an increase in freestream turbulence intensity caused a considerable reduction in both the critical Reynolds number and drag. These variations in the forces acting on the cylinder were related to the behavior of shear layers and wake.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| 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) | 0.000 | 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 teacher head, 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".