An Experimental Study on Vortex Induced Motion of a Submerged Cylindrical Buoy With a Short Tether Chain
Bibliographic record
Abstract
Abstract Here we study experimentally the Vortex Induced Motion (VIM) of a cylindrical subsurface buoy tethered by a short chain. This system has 5 degrees of freedom (DOF), but can experience 3 DOF in translation (heave, surge and sway) and 3 DOF in rotation (yaw, pitch and roll). Previous studies focused on buoys with high ratio between tether line length and buoy diameter, which led to only 3 DOF motions (surge, sway and yaw). We put a reduced model buoy in the test section of a hydrodynamic loop. The mass ratio of the buoy was of 0.213, its slenderness ratio of 3.95, and the ratio between the tether line length and the diameter of the cylinder was of only 1.99, compared to around 15 in previous studies. Reduced velocity Ur ranging from 1.55 to 10.8 have been tested. The buoy was captured crosswise, and we got its surge and heave motions and the orientation of the buoy in terms of yaw, pitch and roll motions. Sway was not obtained in a satisfying way. Eventually, we found significant heave, surge, sway, yaw, pitch and roll motions above Ur ≈ 4. These motions were mostly harmonic, but with a irregular superimposed component, which was probably due to the turbulence of the flow. We did not observe any clear lock-in phenomenon, and the roll frequencies were always lower than Strouhal frequencies.
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".