Effects of Flow Pulsing on Passive Scalar Mixing in a Turbulent Round Jet
Bibliographic record
Abstract
This work presents a study on the effect of pulsing on a jet flow. Puls- ing is used to modify jet inlet conditions with the objective of improving mixing. In this experimental work, a jet was slightly heated so that temperature could be considered as a passive scalar. The spectral behaviour of velocity and the passive scalar temperature was analyzed along the jet axis with and without pulsing. Low frequency pulsing (f/fS < 0.05 fS the Strouhal frequency) modifies the spectral com- position of the velocity at the jet exit, but it does not affect the asymptotic profile reached in the fully developed region of the jet at approximately x/d = 30. The lower frequency pulsations travel far downstream and stay visible in the fully de- veloped region on both the velocity and temperature spectra. This pulsing affects slightly the scalar spectral composition at the jet exit for only the highest frequency used (f/fS = 0.04 (40 Hz) to 0.05 (80 Hz)). This indicates that mixing is improved since the change reflects mixing the main flow with the surrounding airflow. Also, the presence of low pulsing frequencies far downstream indicates the effect pro- duced at the jet exit lasts into the far field.
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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 | 0.001 |
| 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 | 0.001 |
| 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".