On the dynamics of perching manoeuvres with low-aspect-ratio planforms
Bibliographic record
Abstract
The dynamics of a simple perching manoeuvre are investigated using circular and aspect-ratio-two elliptical flat plates, as abstractions of low-aspect-ratio planforms observed in highly-manoeuvrable birds. The perching kinematic investigated in this study involves a pitch-up motion from an angle of attack of [Formula: see text] to [Formula: see text], while simultaneously decelerating. This motion is defined by the shape change number, [Formula: see text], which acts as a measure of the relative contributions of added-mass and circulatory effects. This motion has been observed in natural flyers during controlled landings, and has recently been explored through the use of a nominally two-dimensional airfoil. The parameter space of low-aspect-ratio plates therefore serves to elucidate how realistic free-end conditions affect the timescales of vortex evolution, and therefore the relative contributions between added mass and circulation. The results presented herein suggest that for the low-aspect-ratio plates, the shedding of vortices occurs more rapidly than for equivalent two-dimensional cases, and therefore faster pitching motions are required to compensate for the lower levels of lift and drag. Furthermore, the vortex topology and instantaneous forces that arise during the rapid-area changes show no sensitivity to aspect ratio, and strong collapse is observed between both flat plates. Similar aerodynamic advantages may therefore be exploited during perching manoeuvres by birds of various scale regardless of wing aspect ratio.
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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 | 0.000 |
| 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".