DIRECT SIMULATION OF TRAILING-EDGE NOISE GENERATED BY A CONTROLLED DIFFUSION AIRFOIL USING A LATTICE-BOLTZMANN METHOD
Bibliographic record
Abstract
Broadband noise produced by the trailing-edge of a controlled diffusion (CD) airfoil is directly simulated using a Lattice-Boltzmann method (PowerFlow) which resolves both the aerodynamic and acoustic field around the airfoil.A proper DNS resolution is achieved in the vicinity of the airfoil for quasi-2D slice of the mock-up.Two numerical setups of the anechoic open-jet facility where both aerodynamic and acoustic data have been collected are investigated to capture the installation effects: in a first numerical setup (called free), the CD airfoil is set in an uniform flow, while in the second setup (lips) the real jet nozzle geometry is considered.While in the free-field configuration the boundary layer rapidly detaches on the suction side, in the lips the jet shear layers modify the pressure load on the airfoil and the boundary layer keeps attached in the configuration with nozzle.In both setups a laminar recirculation bubble is captured on the suction side near the leading edge.At the reattachment point vortices are emitted and convected either in the wake for the detached flow or along the suction side for the lips setup.The wallpressure and noise spectra for the free configuration are spread over a large band of frequencies and agree with similar experimental records at higher angle of attack for which the flow is detached.The spectra for the lips configuration better agree with the experimental record, despite a shift to low frequency caused by a lack of stretching due to the limited span-wise extent.
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 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".