Internal and Blade Surface Pressure Measurements of Centrifugal Flow Control on a Large Scale Rotor
Bibliographic record
Abstract
A large scale rotor test has been performed to evaluate concepts for improving the high thrust and high speed capabilities of an edgewise single rotor helicopter. The primary approach was to alleviate dynamic stall using centrifugally pumped steady blowing, referred to as Retreating Side Blowing (RSB). This concept was studied earlier for an airfoil with a flow control slot able to generate momentum coefficients of 0.03 to 0.05 using computational simulation and experiment. The current experiment uses a 28 ft diameter rotor having an inlet at the blade root, a hollow spar, and a series of flow control slots from 65% to 95% of the radius. It was tested at the Sikorsky Main Rotor Whirl Stand and at the National Full Scale Aerodynamic Complex. Rotor performance and structural load data were acquired for multiple configurations at advance ratios of 0.24 to 0.61. This paper focuses on the internal pressure measurements used to determine the performance of the centrifugal pumping system in hover and in forward flight, and on the external pressure measurements used to define the effect of the slot blowing on the dynamic stall characteristics. While the centrifugal flow control system generated the expected mass flow, the impact on blade dynamic stall characteristics and rotor performance was less than desired. The rotor results are compared to those from the airfoil test and to prior flow control rotor tests.
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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".