Flow development and structural loading on dual step cylinders in laminar shedding regime
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
The flow development over a dual step cylinder is investigated numerically at a Reynolds number (ReD) of 150 for a range of aspect ratios, 0.2 ≤ L/D ≤ 5, and diameter ratios, 1.1 ≤ D/d ≤ 4. The results reveal the following four distinct types of wake topology downstream of the larger diameter cylinder: (i) shedding of hairpin vortices, (ii) transient asymmetric shedding, (iii) primarily spanwise shedding, and (iv) no vortex shedding. Dominant vortex interactions are reconstructed for each regime. These interactions, involving half-loop vortex connections, vortex merging, and direct vortex connections are shown to occur periodically as the large and small cylinder structures undergo vortex dislocations. Topological schematics are introduced to relate the characteristic frequencies to the periodic vortex interactions. The observed types of wake topology are shown to produce distinctly different mean and fluctuating forces on the dual step cylinder. For lower aspect and diameter ratios (L/D ∼ 1 and D/d ∼ 1.5), a reduction in fluctuating lift of up to 80% can be achieved on the base cylinder with a minor reduction in mean drag (∼5%). The results indicate that similar performance improvements can be sustained by attaching multiple larger diameter cylinders to the base cylinder. The changes in the fluid forcing are shown to be related to the secondary flow produced by the downwash at the stepwise discontinuities. This process also involves the production of streamwise vorticity at the steps, which is shown to be associated with the deformation of the main spanwise vortical structures.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 it