Unsteady Heat Transfer During the Rapid Compression and Expansion of Air
Bibliographic record
Abstract
The instantaneous unsteady heat transfer during rapid compression and expansion of air within a pneumatically driven piston in a cylinder arrangement which offers simple, well-controlled and known boundary conditions was examined. Values of the instantaneous apparent overall heat flux from the cylinder gas to the wall surfaces were calculated using a thermodynamic analysis of the experimentally measured pressure and volume temporal development. Corresponding heat flux values were also calculated through the application of a zero-dimensional model that incorporates the use of the k–ε turbulence model. Comparison of the results of the model with corresponding experimental data showed fair to good agreement for the wide range of compression ratio values used (8.4∼24.3). Also, correlation of the derived data using an effective velocity which is based on the distribution of mean kinetic energy, turbulence energy and piston motion and a characteristic length that is a function of the instantaneous height between the piston top and the cylinder head and bore diameter as the parameters to use when calculating the Reynolds, Prandtl and Nusselt numbers resulted in the following workable relationship: Nu = 0.01Re0.205 Pr0.033.
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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".