Time-averaged flow field behind a transversely spinning sphere: An experimental study
Bibliographic record
Abstract
The aerodynamic forces on a sphere with a rough surface were measured in a water tunnel at a Reynolds number of 7930 and for a range of spinning ratios (α) from 0 to 6.0. The time-averaged flow fields were also measured using particle image velocimetry. The effect of the spinning ratio α on the flow was found to show distinct trends in different regimes, including α≤0.25; 0.25<α≤0.75; 0.75<α≤2.0; 2.0<α≤3.0; and 3.0<α≤6.0. The study identified two critical spinning ratios, where the flow underwent significant changes. The first change occurred in regime II, where the boundary layer over one side of the sphere transitioned from laminar to turbulent, leading to a significant modification in the lift force on the sphere. The second significant change took place across regimes II and III, where the boundary flow in the vicinity of the entire sphere became turbulent. Beyond this range, with α≥3.0, the high spinning rate disturbed the incoming flow, resulting in less-efficient downwash production. The lift increased with α at a slower rate compared to other regimes, and the less-efficient downwash production caused a decrease in drag as more momentum was directed downstream in the horizontal direction.
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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 | 0.000 | 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".