Turbulent Transition Impact to Production Design Model- and Full-Scale Hovering Rotor Performance
Bibliographic record
Abstract
Impact of laminar-turbulent flow transition to hovering rotor performance is assessed using both model- and full-scale rotors. Helios is used for all simulations using OVERFLOW as a near-body solver. The Langtry-Mentor transition model is validated against Hover Validation and Acoustic Baseline (HVAB) rotor test data using industry best practice modeling approach. The same modeling approach is validated with model-scale production design rotor to assess its applicability to different blade design including different airfoils, twist, and planform shape. The validated modeling approach is then used for full-scale rotor to assess impact of transition for high Reynolds-number full-scale rotor performance. The full-scale rotor performance is also compared with whirl-tower test data. For all three rotors, rotor figure of merit is compared for range of thrust against test data. Transition locations and blade loading distributions are also compared. Sensitivity studies were also performed including facility impact, control system stiffness effect, and wind impact. The current transition modeling approach showed very good correlation with both model-scale test data in integrated figure of merit. However, differences with test data were observed in detailed blade loading and surface suction pressure at outboard region where blade-vortex interaction occurs. The full-scale rotor simulation also showed reasonably good correlation in performance but with simulation results being slightly optimistic in both fully turbulent and transition model, with transition model being little more optimistic. The laminar-turbulent flow transition trend from model- to full-scale seems reasonable, although, with more uncertainties in the full-scale test results, it was hard to determine quantitative transition model impact validation. Findings from current study is used to guide future hover performance simulations, and to understand model- and full-scale rotor performance difference.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".