Characteristics of the flow over a NACA 0012 airfoil at low Reynolds numbers
Bibliographic record
Abstract
This paper presents our work of an experimental examination of the flow over a NACA 0012 Airfoil at low Reynolds numbers and large angle of attack using particle imaging velocimetry.The Reynolds numbers examined were 5,000, 30,000, and 60,000, while the angles of attack ranged from 8 to 12 degrees in 2 degree increments.This work was motivated by reports that lift and drag measurements for airfoils operating at Reynolds numbers less than roughly 40,000 could not be made due to flow unsteadiness.This is puzzling in that the flow should be laminar at these Reynolds numbers, which are an order of magnitude lower than the flat-plate transition Reynolds number of 500,000.To this end we examined a sequence of flow field measurements of the instantaneous velocity field.We observed mean streamline patterns that were very representative of those we would find for a strictly steady flow, however a random pattern of significant fluctuations in the velocity and vorticity were observed.The intensity of these fluctuations increased with Reynolds number and angle of attack.
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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 | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".