Shifted Cross-Wire for Supersonic Jet Control
Bibliographic record
Abstract
*† ‡ This paper presents the results of an experimental investigation carried out to study the effectiveness of a passive control in the form of a cross-wire located downstream of nozzle exit for promoting the jet mixing. The specific advantage of this kind of control is that the precious nozzle exit area is not blocked, this avoids thrust penalty. The characteristics of Mach 1.83, 1.86 and 1.94 jets from Laval nozzles of rectangular crosssection operated at correctly expanded, overexpanded and underexpanded conditions were investigated with cross-wire at axial distances of 0.5De, 1.0De, 1.5De and 2.0De. The shifted cross-wire is found to be an effective mixing promoter. The shocks in the core become weaker when the cross-wire is placed. Compared to its uncontrolled counterpart, the controlled jet propagates at a significantly reduced Pitot pressures. With crosswire, a maximum core reduction of 30% was achieved for Mach 1.86 jet at NPR 7. The cross-wire at 1.0De location is found to be most effective in mixing promotion for the present scheme. Further, this control effectiveness is significant both in the overexpanded and underexpanded cases. In addition to shifted crosswire, cross-wire located at the exit of the nozzle was studied to estimate the thrust loss incurred and found that the thrust loss is nearly equal to the blockage area.
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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".