Bibliographic record
Abstract
The flow-acoustic nature of sharp-edged T-junctions is investigated experimentally. In this paper, the pipes forming the T-crossbar are referred to as the branches and the pipe forming the central stem of the T-shape is referred to as the main pipe. Four test cases are studied corresponding to: (a) T-junction with flow from each branch into the main pipe; (b) T-junction with flow from one branch into the main pipe, the other branch being closed; (c) T-junction with flow from the main pipe into the two branches, which is the reverse flow situation of the first case; and (d) T-junction with flow from the main pipe into one branch and the other branch is closed, which is the second case with reverse flow. It is found that the flow at the T-junction can excite the pipe acoustic modes to varying degrees, depending on the flow direction and piping configuration. For cases (c) and (d), the dimensionless pressure amplitude of the acoustic mode reaches a maximum at a Strouhal number similar to that of the turbulence broadband peak measured in the separation bubble downstream of the T-junction corner. Cases (a) and (b) exhibit a different type of flow-acoustic coupling. In both cases, the maximum acoustic pressure occurs at a Strouhal number which is different from that observed in the separation bubble. In addition, the pulsation amplitude is substantially stronger than that observed in cases (c) and (d). Detuning the branches weakens the resonance intensity, especially in case (c), which exhibits the strongest acoustic resonance.
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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 | 0.001 |
| 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".