A new test facility for probe calibration offering independent variation of Mach and Reynolds number
Bibliographic record
Abstract
At DLR, Göttingen, a new facility for probe calibration was built where dried air is driven by two compressors forming a closed circuit system with a free jet test section. Mach number and Reynolds number are the parameters to be varied while the total temperature is kept constant at T0 = 298K (25°C). The Mach number covers the range from Ma = 0.3 to 1.6 and will be extended down to Ma = 0.2 and up to 1.8 when the some modifications in the circuit will be installed. Variation of the Reynolds number is possible via the total pressure which can range from p0 = 30kPa up to 300kPa. There are different axisymmetric nozzles with an exit diameter up to 50 mm to achieve different Mach numbers. First a convergent nozzle covers the subsonic range, second a slotted nozzle is used within the transonic range and third three Laval nozzles are available for supersonic Mach numbers (Ma = 1.4, 1.5 and 1.6). The orientation of the probe head positioned downstream of the exit plane on the centre line of the nozzle flow can be varied from -22° up to +22° for both the angle of attack and the yaw angle using stepping motors. Data acquisition is done by means of a PSI-module (for the most important pressures) and a SIMATIC operating system from Siemens, while the automatic data collection and a first evaluation is done using a software based on LabVIEW. First measurements of the jet quality at different distances from the nozzle exit plane showed that the flow field is well suited for probe calibrations. Then two probes, a pyramid probe to be used in 3D flow fields and a wedge type probe to be used in 2D flow fields were calibrated. These results were already applied when wake traverses were performed in the Wind Tunnel for Straight Cascades (EGG) at DLR, Göttingen. The technical set up of the wind tunnel, first measurements concerning the flow quality and some results of probe calibration will be presented.
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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 | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.003 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.003 | 0.002 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.013 | 0.005 |
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".