Investigating the noise sources of the transonic RAE 2822 airfoil
Bibliographic record
Abstract
A compressible Large Eddy Simulation is performed on the transonic RAE 2822 airfoil, and compared to the baseline simulation of Koch et al. (28th AIAA/CEAS Aeroacoustics Conference, paper AIAA 2022-2816) in order to highlight the main noise source mechanisms.The new simulation employs a new mesh which eliminates a jump in the airfoil surface mesh, located in the supersonic laminar boundary layer region of the suction side.This jump induced some hydrodynamic instability in the suction side boundary layer of the baseline simulation, potentially emitting noise at high-frequencies.The new results show that these instabilities are significantly damped when employing the new refined mesh and are consequently very sensitive to the grid quality.Nonetheless, the acoustic response of the airfoil, calculated using the Ffowcs Williams and Hawkings analogy in its solid formulation, remains similar to the baseline, with a highfrequency hump appearing between 30 and 40 kHz.This shows that this hump is not caused by the hydrodynamic instabilities, therefore confirming the grid independence of the acoustic results.
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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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".