Hypersonic PIV in a Ludwieg Tube Wind Tunnel at Mach 5.9
Bibliographic record
Abstract
The present work describes particle image velocimetry at M = 5.9 in the Hypersonic Ludwieg Tube Braunschweig on a generic space launcher model. The wind tunnel allows high quality flows as well as high repetition rates and, thus, it is suited for PIV-measurements. The PIV-measurements were performed with oil based tracer particles. Two different aerosol facilities, which differ basically in the position of the aerosol inlet, are described and compared. The first aerosol facility is close to the Laval nozzle whereas the second one is at the begin of the storage tube. The influences of both aerosol facilities to the quality of the PIV-measurements as well as to the safety of the wind tunnel are discussed. The results show that oil based PIV-measurements in a hypersonic blow down facility with a heated and pressurized storage tube are possible. The first aerosol facility close to the Laval nozzle results in an inhomogeneous tracer particle distribution with a low repeatability from run to run. The second aerosol facility at the begin of the storage tube enhances the distribution of the tracer particles inside the storage tube. The resulting tracer particle distribution is homogeneous as well as reproducible but the number of the tracer particles is reduced.
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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 | 0.000 |
| 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 | 0.001 |
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".