Spectral-Element/Kirchhoff Method for Fan-Tone Directivity Calculations
Bibliographic record
Abstract
A Kirchhoff integral method is coupled to a spectral-element radiation solver for efficient computations of fan-tone directivities at arbitrary distances from a turbofan inlet The Kirchhoff algorithm accurately constructs the acoustic solution at specified locations in the farfield by processing near-field data supplied by the spectral-element solver. This allows the use of a much smaller spectral-element domain concentrated near the engine that is not required to encompass the specified directivity radius. The use of a smaller computational domain translates into a reduction in overall CPU time and/or an increase in the frequency limit of the code. This paper presents a detailed description of the theory, implementation, and validation of the Kirchhoff algorithm. Numerical studies are performed to address the following issues: 1) optimal placement of the Kirchhoff integration surface in the presence of a locally non-uniform mean-flow; 2) impact of a partially opened Kirchhoff surface on the accuracy of the predicted directivity. The spectral-element/Kirchhoff system is further demonstrated by computing inlet radiation directivities up to a radius of 150 feet for practical engine power conditions and frequencies. Copyright © 2005 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
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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".