Later Stages of Transition over a NACA 0018 Airfoil at Low Reynolds Numbers
Bibliographic record
Abstract
The later stages of laminar-to-turbulent transition in a separation bubble are investigated in this work. Wind tunnel experiments were performed on a NACA 0018 airfoil at a chord Reynolds number of 10 and an angle of attack of 5. At these experimental conditions, a separation bubble forms over the suction side of the airfoil. Surface pressure velocity measurements were performed to estimate separation bubble characteristics. A rake of five hot-wire probes, evenly spaced in the spanwise direction, was used to investigate streamwise and spanwise development of fundamental disturbances leading to separated shear layer transition. Cross-correlation results show that, within the region of initial exponential growth, the disturbances are strongly correlated along the span, implying two-dimensional development in this region. This is followed by a sharp decrease in spanwise correlation coincidental with the broadening of the spectral content across a wider range of frequencies during the later stages of the transition process. However, for the conditions investigated, a weak frequency centred activity persists at the fundamental frequency in the aft portion of the bubble. Analysis of the cross-correlation results suggests that this is linked to the development of shear layer roll-up vortices, which undergo significant spanwise deformations during the last stages of transition.
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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".