Random Incidence Sound Absorption of Porous Materials With Periodic Holes of Decreasing Profile
Bibliographic record
Abstract
This study investigates the acoustic performance of porous materials incorporating embedded periodic holes with a decreasing profile. Finite element simulations are used to assess the sound absorption coefficients and surface impedance under both oblique and random incidence (diffuse field) conditions for materials with low and high airflow resistivity. Acoustic field analysis reveals that while low-resistive materials support plane wave propagation, higher resistivity induces pressure diffusion, disrupting wavefront uniformity. For incidence angles up to 45 deg the diffuse field sound absorption coefficient is higher than 0.99 from 250 Hz to 3000 Hz and presents a peak of 0.98 at 110 Hz. As the incidence angle increases, the acoustic velocity through the material decreases and tends to zero as the incidence angle approaches 90° and the surface impedance increases and consequently the absorption coefficient decreases. The introduction of periodic holes significantly improves low-frequency diffuse field sound absorption compared to traditional porous materials, demonstrating the potential of this design for real-life acoustic applications.
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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".