Numerical simulation of drag reduction for turbulent flow in cylindrical annuli with axial corrugations
Bibliographic record
Abstract
A computational fluid dynamics study has been undertaken to determine the effect of axial corrugations on the inner and outer surfaces of cylindrical annuli in the turbulent flow regime. Results show that axial corrugations on either one or both surfaces has the potential to reduce drag for certain types of corrugations. Overall, it is found that drag reduction is increased with larger amplitude and longer wavelength corrugations. Corrugations on the inner and outer cylinders have similar effect to one another and can be combined on both surfaces for greater drag reduction than the sum of the individual effects. If corrugations are present on both surfaces, an out-of-phase arrangement is shown to yield the best drag reduction. An eccentric alignment of the inner cylinder is also shown to increase potential for drag reduction for the parameters considered in this study. Within the turbulent flow regime, it is shown that the Reynolds number has a weak effect on the potential drag reduction. For the geometries considered in this study, the drag reduction potential is up to approximately 25%.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 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".