A Study of Noise Generation by Turbulent Flow Instabilities in a Gas Turbine Model Combustor
Bibliographic record
Abstract
Due to successful noise reduction strategies concerning fan- and jet-noise in gas turbine configurations, the relevance of combustion noise is increasing. In order to distinguish between turbulent noise and combustion noise a model gas turbine combustor consisting of a swirl burner and an exit nozzle of Laval-shape is investigated. Because of the instationary character of the flow this configuration is analysed by means of Large Eddy Simulation (LES). Numerical results are first validated by comparison with experimental data. Then a numerical study of noise generated by turbulent flow instabilities is carried out. Providing an extensive temporal and spatial analysis of the isothermal flow length- and timescales as well as vorticitiy are investigated with regard to the formation of rotating flow-instabilities in the recirculating swirling flow. Subsequently a link to the acoustic perturbation equations (APE) is provided, from which the Lamb vector represents the essential noise sources. Therfore noise sources are identified and evaluated by means of LES based on the Lamb vector consideration. It results that the noise sources increase with an increasing swirl number.
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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".