Ice Crystal Environment Modular Axial Compressor Rig: Variable TWC Accretion Studies
Bibliographic record
Abstract
In May 2023 the Federal Aviation Administration in collaboration with the National Research Council of Canada performed research on altitude ice crystal icing of aircraft engines using the compressor rig, ICE-MACR, in an altitude wind tunnel. The aim of the 2023 research was to address research needs related to ice crystal icing of aircraft engines outlined in FAA publication Engine Ice Crystal Icing Technology Plan with Research Needs. This work continues the efforts to provide a fundamental understanding of the ice crystal accretion process and was focused on the onset of accretion in the turbofan engine. This testing provided useful information for analytically assessing an engine’s capability in the ice crystal icing environment. Heat flux gauge analysis in these tests gave insight for the processes occurring at the icing surface when the wet bulb temperature based on total conditions is above freezing and optimum icing occurs. In natural ice crystal icing clouds, total water content (TWC) is variable, and understanding the effects on accretion is key to defining the icing exposures that need to be considered to fully assess an engine in the icing envelope. Test results are presented to shed light on precooling the icing surface with a low TWC and how that affects subsequent exposure to high TWC. These results show the effect of precooling reduced the heat to be removed from the surface before ice formed, shortening the time for ice accretion to begin. Precooling also required less total ice exposure to achieve transition to steady growth. Another simulation of natural cloud variation investigated high to low TWC to better understand whether ice would continue to accrete when the TWC is decreasing, as expected on exiting an icing cloud. These test points assessed whether once ice has formed on a surface it can continue to grow if the TWC is reduced below the threshold of accretion. The threshold of accretion is the highest TWC under which ice will not form even though conditions provide favorable temperatures and melt for ice formation. Analysis of the high to low TWC test points defined the conditions needed for further ice growth after a switch to low TWC. Video analysis and detailed temperature and heat flux data are used to present results for the variable TWC cloud scenarios.
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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) | 0.000 | 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 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".