The Development of the Turbulent Three-Dimensional Wall Jet With and Without a Grid Placed Over the Outlet
Bibliographic record
Abstract
The three-dimensional turbulent wall jet has a lateral half-width that is 5 to 8 times greater than its vertical half-height. This has been previously attributed to strong turbulence generated secondary flow caused by the passage of coherent vortex-ring structures formed at the nozzle exit. In order to assess whether the large lateral growth of the jet is tied to these structures, a grid was placed at the nozzle exit to disrupt the shear-layer that produces the vortex rings at the outlet. Here, the jet was formed using a 0.038m round contoured nozzle with an exit Reynolds number of 108,000. The grid has a mesh wire size of 0.2mm with an opening of 1mm giving it a solidity ratio of 0.4. Measurements of the jet with and without the grid were taken using hot-wire anemometry and stereoscopic Particle Image Velocimetry (PIV). The results indicate that the grid delays the lateral growth of the jet and increases its vertical growth. By x/D=40 though, these differences were minimal. The presence of the grid also decreased the mass entrainment and mixing associated with the jet at each downstream location investigated.
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.
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 | 0.001 | 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".