Linking microstructure and acoustic properties of open-cell foams
Bibliographic record
Abstract
A research program has been initiated in 2002 in order to link microstructure of high porosity open-cell foams to their acoustic properties. This paper is intended to highlight the main results of this study. The general objective of the research program is the determination of the acoustical macro-behavior from the physics at the local scale. A real rigid-framed porous media is studied. To this end, one needs first to determine the local geometry of the media, and second to solve over this geometry the partial differential equations that govern dissipation phenomena by thermal and viscous effects. The first step has been overcome by the technique of computed microtomography. This leads to experimental identification of the parameters of an idealized periodic unit-cell. The second step, solving harmonic heat and viscous fluid equations, is performed using Brownian motion and finite element simulations, respectively. Then, macroscopic behavior is obtained by spatial averaging of the local and frequency-dependent thermal and velocity fields. Results are presented in terms of two dynamic characteristic functions (viscous and thermal permeabilities) compared to impedance tube measurements. This computational methodology may be seen as a first step to optimize the microstructure of foams from a bottom-up approach for better sound proofing.
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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) | 0.000 | 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 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".