On the crown formation and cavity dynamics of free-falling thick disks
Bibliographic record
Abstract
The water entry, crown formation, and cavity dynamics of gravity-driven thick solid and annular disks were studied by conducting a series of detailed laboratory experiments. Three different release conditions were examined to study the fully guarded and partially guarded release conditions on the cavity dynamics. The effects of aspect ratio, geometry, and density of disks on crown formation, interface impact, seal development, and air entrainment were investigated. Four crown shapes were identified, and the crown structure was classified based on the dimensionless moment of inertia, I*, and the impact Froude number, Fro. The effects of controlling parameters on variations of crown dimensions were investigated. It was found that the normalized crown diameter decreased with I* and crown geometries were found to be smaller in annular disks. Experimental observations have shown that high-density disks have larger pinch-off depth and form a deep seal in the ambient water. The normalized pinch-off depth increased with Fro and the normalized pinch-off depth in cylindrical thick disks were smaller than thin disks and spherical objects. The temporal variations of cavity indicated a non-linear correlation between the growth rate of normalized pinch-off depth and time. The disk's velocities in three different stages were measured, it was found that the settling velocities followed a linear relationship with I*, and it was affected by the release conditions. The velocity and vortex fields were extracted from the particle image velocimetry data. The velocity fields showed that the solid disks affected a greater surrounding ambient in comparison to the annular disks due to their higher initial momentum. Periodic vortex shedding was formed in the wake of annular disks, and the frequency of the vortex field was found to be proportional to the disk density.
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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 | 0.000 | 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 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".