The Measurement and Application of Trailing-Edge Noise in the UTIAS Hybrid Anechoic Wind Tunnel
Bibliographic record
Abstract
Turbulent boundary layer trailing-edge noise is a fundamental aeroacoustic noise source present in a variety of applications, including aircraft geometries, fans, and wind turbine blades. Understanding and controlling the source mechanisms of trailing-edge noise is an area of ongoing experimental research. In this work, trailing-edge noise has been applied as a benchmark noise case for a hybrid anechoic wind tunnel, an example of which has been recently constructed at the University of Toronto. This facility type is expected to offer advantages in replicating conditions for aeroacoustic sources at high angles of attack. The aerodynamic capabilities of the facility are demonstrated by measuring and analyzing the lift characteristics and boundary layer properties of a tripped two dimensional NACA 0012 airfoil at angles of attack between 0 and 15 degrees and freestream velocities between 20 and 50 m/s. The acoustic performance is then shown by comparing analytical models for the surface pressure fluctuations and far-field acoustic signature with measurements of the airfoil at zero degrees angle of attack. These comparisons reveal that trailing-edge source mechanisms are successfully produced and measured. However, spurious junction noise and background noise sources make isolation of the far-field acoustic signature challenging, suggesting some modifications that would further improve the hybrid tunnel's capabilities. Further acoustic characteristics of the facility are investigated using the Aeolian tone from a cylinder and a monopole point source from laser induced plasma, indicating satisfactory performance. Trailing-edge noise results are then extended to higher angles of attack, where the hybrid wind tunnel's ability to maintain expected flow conditions is demonstrated. Thicker boundary layers are observed, producing changes in the noise mechanisms as the airfoil approaches separation and stall. Investigations of the surface pressure fluctuations and acoustic signature reveal a shift to lower frequencies and an increase in noise amplitude due to the dominance of larger structures in the airfoil boundary layer.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 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".