A Spatio-Temporal Decomposition of the Acoustic Source in a Mach 0.85 Jet
Bibliographic record
Abstract
Multi-point measurements of the near-field pressure around the periphery of a cold Mach 0.85 round jet were performed simultaneously with far-field acoustic pressure measurements to examine the spatial and temporal character of the acoustic source in the jet. A Fourier decomposition of the near-field pressure indicates that the majority of the energy is relatively evenly split between azimuthal modes 0 and 1. Only azimuthal mode 0, however, made a significant contribution to the near-field/far-field pressure cross-spectrum indicating that the acoustic source in the jet is axisymmetric. The largest contribution of azimuthal mode 0 was for low wavenumbers commonly associated with hydrodynamic pressure fluctuations, indicating that large, low frequency hydrodynamic fluctuations are hiding the dominant acoustic source in the jet.
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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 | 0.001 | 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".