Efficient control of the fully passive oscillating foil in 2D confined flows with adjustment of the heave damping
Bibliographic record
Abstract
A foil that is free to pitch and heave in an upstream flow can oscillate very regularly and with large amplitudes given that its inertial properties and support stiffness in pitch and heave are well adapted to the flow velocity. Useful energy can be extracted from these oscillations via an appropriate damping in heave that models the presence of an electric generator. In recent years, the structural parameters of such a fully passive oscillating-foil turbine (OFT) have been optimized, yielding a maximum energy extraction efficiency of 51.0% under the assumptions of 2D and unconfined flow. However, the turbine is normally deployed in channels with finite cross-sectional area, thus impacting the flow rate passing through the turbine via the blockage effect. In this work, we extend the applicability of the 2D optimized structural parameters to 2D confined scenarios with a simple tuning of the viscous heave damping coefficient. Performance is determined via a fluid-structure interaction solver based on an unsteady Reynolds-averaged Navier–Stokes approach. As expected, confining the turbine increases the heave amplitude and the power, up to a point where the motions become chaotic, and thus require an increase in the heave damping coefficient. This study shows that in all confined 2D scenarios, reasonably good performances of the fully passive OFT can be maintained when using its optimal structural parameters obtained in 2D unconfined conditions, given that the generator is adjusted accordingly.
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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".