Experimental Analysis of Swirl in Short Annular Diffusers With Negative Wall Angles
Bibliographic record
Abstract
Short annular diffuser systems consisting of a conical expansion section with negative wall angles and a solid (full outer diameter) diffusing section were tested experimentally at several inlet swirl angles of 0–40°. Tests analyzed were completed over a range of inlet Reynolds number of Ret = 0.9–2.2 × 105 and considered fully turbulent. Performance — back pressure coefficient, outlet velocity uniformity, and total pressure loss — were appreciably depreciated for inlet swirl number larger than 0.7 and the average 10° curved vane swirler out-performed its straight vaned equivalent. Three centre bodies with length half that of the diffuser and different curvatures were manufactured. Similar performance was achieved but each centre body provided marginal improvements to a particular objective. Most notably, the centre body that gave an initial flow expansion angle of 14° resulted in 1–4% lower back pressure than the other two whose expansion angles were 12° and 16°.
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 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 | 0.001 |
| 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 teacher head, 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".