Preliminary acoustic performance investigation of concentric-tube perforated muffler design
Bibliographic record
Abstract
Two impendence models based on the theoretical and empirical results are compared using a one dimensional segmentation method to explore the differences in predicted transmission loss (TL) of a concentric-tube perforated muffler with zero mean flow. Simulations demonstrate that perforated tube mufflers have better acoustic attenuation properties than simple expansion chamber mufflers. These perforated tube elements are widely used in resonators and mufflers to attenuate exhaust system noise. The physical segmentation or simplification of the perforated tube includes the effect of perforation in each segment, which is considered as a branch with a solid tube connecting the branches of each adjoining segment. A one dimensional segment model is compared with Ricardo WAVE, a commercial software modeling package. Results show that large discrepancy in prediction of transmission loss is found between the WAVE for a large perforated muffler configuration.
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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 | 0.001 |
| 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".