Pros and cons of equipping Harmonic Acoustic Pneumatic Sources (HAPS) with quarter wave tube: analytical model versus experimental validation
Bibliographic record
Abstract
Pneumatic acoustic sources enable high Sound Pressure Levels (SPL). Harmonic Acoustic Pneumatic Sources (HAPS), utilizing airflow modulation to create precise acoustic pressure fields with controlled amplitude and phase, emerge as solutions for active harmonic-noise control at high SPLs. While theoretically capable of generating pure tones, HAPS appear to be non-linear sources with significant harmonic distortion in practice. Additionally, the mass airflow consumption of this source could be a drawback in certain applications. The aims of this study is to evaluate the advantages of a Quarter-Wave Tube (QWT) located at the HAPS output. A numerical analytical linear model has been developed to compute the radiated acoustic pressure and consumed mass air flow, according to the QWT and HAPS characteristics. For the cases of HAPS equipped with various QWT, this presentation will compare experimental results with the analytical model. This aims to highlight the advantages, including increased SPL of the radiated fundamental, reduced fundamental/harmonic distortion over a wide frequency range, and decreased airflow consumption. The disadvantage is related to the space required by the QWT because its diameters must be greater than the HAPS output. Whatever, this study demonstrate that HAPS can be improved when equipped with a dedicated exhaust.
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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".