Experimental Study of a Flexible Oscillating-Foil Propulsion System With Variable Stiffness and Inertia
Bibliographic record
Abstract
Considerable effort has been devoted to the development of flexible flapping fins and wings as propulsion mechanisms for robotics applications. The present work contributes to this research field by considering the effects of inertia, stiffness, resonant frequency and oscillation kinematics on the thrust generation and efficiency of flexible oscillating foils. The findings are derived from experimental measurements of the forces applied to foil models, which were undergoing an oscillating motion in water. In addition, a semi-empirical model of the foil structure was developed to characterize the fluid-structure interaction phenomena. The ratio of the oscillation frequency to structural resonant frequency was found to be one of the principal parameters, which determined the propulsive efficiency. However, when comparing the performance of foils with equivalent resonant frequencies but different levels of stiffness and inertia, stiffer and heavier foils were found to achieve greater thrust production. The improved performance of the heavier foils compared to lighter ones is attributed to a decrease in the damping ratio. The lower damping ratio allowed for a greater amplitude of the motion of the deforming part of the foil which resulted in increased thrust.
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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 | 0.000 | 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 | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| 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".