Correlation between single-wire and multi-wire tripping of the flow past a circular cylinder
Bibliographic record
Abstract
Abstract An experimental study is carried out to explore if the collective influence of multiple tripwires applied spanwise on a circular cylinder can be correlated to the well-known effects of single-wire tripping from previous studies. Constant Temperature Anemometry and Particle Image Velocimetry tests were conducted on single-wire- and two-wire-fitted cylinders in subcritical flow. Noting that a single tripwire can only influence the shedding frequency when it is within a certain range of locations on the cylinder surface, two scenarios for two-wire-fitted cylinders are noteworthy: (1) One of the two wires can fall within this range of locations. This is the case where flow features for the two-wire-fitted cylinder are identical to the single-wire-fitted one. In this category, the Karman vortex shedding loses its coherence and a bistable separation behavior sets in when the influential wire is at the first critical location (+/− θ c 1 ) of the single-wire application. (2) Both tripwires can be in the range of locations where the single tripwire application influences the shedding frequency. This is the scenario where flow is controlled by both tripwires. The most dominant influence comes from the tripwire that is closer to the θ c location (another critical location identified by previous studies for single-wire applications). Furthermore, in this category, the drastic attenuation of the Karman instability and the onset of the bistable shear-layer separation occur when one of the wires is at a new θ c 1 location that is about 5°–7° larger than the θ c 1 reported for single-wire tripping by previous studies. This change in θ c 1 comes together with a large degree of near-wake contraction to satisfy the simultaneous entrainment demand needed for the early transition of both shear layers in the two-wire-fitted case. A shortage of fluid in satisfying such an increased entrainment demand is speculated to be the cause of the observed shift in θ c 1 .
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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 | 0.001 | 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".