Prediction of sound absorption characteristics of orifice plates with mean flow using the lattice Boltzmann method.
Bibliographic record
Abstract
The purpose of this study was to evaluate the sound absorption characteristics of orifice plates in turbulent mean flows using numerical simulations. The production of vorticity at the orifice edge governs the sound absorption phenomena. The LBM-LES methodology was used to perform detailed numerical simulations of the unsteady turbulent field. The lattice Boltzmann method has several advantages over continuum based CFD methods for situations where the configurations of the duct, the orifice, and the flow structures through or in contact with porous/perforated media are geometrically complex. The absorption coefficient and the impedance of the perforated plate were obtained in a virtual three dimensional (3-D) impedance tube apparatus. Both the mean flow velocity profiles and the acoustic characteristics of a simple circular orifice were found to be in good agreement with available experimental data. The model was then exercised to investigate the acoustic properties of orifices with complex shapes over a range of mean flow velocities.
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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 | 0.002 |
| 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 | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".