Effects of Injection Angle on the Structure of Choked Gaseous Jets
Bibliographic record
Abstract
The effects of injection angle on the structure of choked gaseous jets injected into quiescent air is investigated experimentally. The study is motivated by the use of choked gaseous jets in many industrial applications, including gas turbines, flares, and burners. The test conditions were as follows: a choked gas jet injected into a quiescent air environment, a straight cylindrical nozzle with an exit diameter of 1.6 mm, and three (3) injection angles of 0° (normal injection), 15°, and 30°. The diagnostics included particle image velocimetry using pulsed Nd:YAG lasers. The jet was seeded with aluminum oxide (1-micron) particles and was injected into an environment that was seeded with water-based fog. The field of view was limited to 22mm x 22mm. The results included jet and entrainment flow velocities and vorticity fields. A computational study of the present three nozzles, by our collaborators, was used to validate and interpret the present experimental results. The experimental results showed that the increase of the injection angle of the nozzle, from the normal position, caused the jet structure to become asymmetric and partially blocked the nozzle exit. This was due to the generation of a velocity slip plane inside the injection port initiating at the leading edge of the inlet section of the nozzle. The sharp entrance edge of the nozzle acted as the nozzle's throat and triggered an expansion fan that accelerated the flow to supersonic speeds of Mach 1.4 for the present test conditions from a simple straight cylindrical nozzle without the use of the traditional convergent-divergent (De Laval) nozzle geometry.
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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.002 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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 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".