Finite Element Study of Perfect Sound Absorbing Porous Material with Periodic Conical Hole Profile
Bibliographic record
Abstract
Porous materials are widely used in several engineering applications for noise reduction. The acoustic performance of these materials at low frequency is low and depends on their acoustic penetration depth or critical depth. When the thickness of the porous material is equal to the critical depth, the sound absorption reaches its asymptotic limit so that a further increase in the material thickness does not improve the absorption coefficient. To overcome this limitation, a porous material design with a periodically distributed conical hole is proposed and its acoustic performance is investigated using the finite element method. Compared to a conventional porous layer, the total mass of the proposed design is reduced and its sound absorption coefficient is significantly improved over a large frequency band. This material design with periodic conical hole is coupled with other conventional porous materials to create a multi-layered system that shows efficient sound absorption performance. The proposed material design can be used as anechoic termination and help in several other applications for noise reduction.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 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".