A Comparison of Circular Duct and Real Hexagonal Duct Results Using Hydraulic Diameter
Bibliographic record
Abstract
To see whether the turbulent flow correlations derived for circular ducts can be used for hexagonal cross-sectional ducts using hydraulic diameter, turbulent flow in hexagonal ducts is numerically investigated under constant wall temperature boundary condition using ANSYS Fluent 17.0 software. Investigated parameters are the Reynolds number between 10×103Re50×103 and side angle of the duct varying between 30o and 90o. Standard k-ε model is used as turbulence model. General expressions are proposed for fully developed dimensionless heat transfer coefficient Nusselt number and fully developed Darcy friction factor in terms of Reynolds number and side angle for hexagonal-shaped cross-sectional duct. Results show that side angle of hexagonal duct affects the pressure drop along duct and heat transfer coefficient in duct. Results point out that regular hexagonal duct, =60o, gives minimum pressure drop and maximum Nusselt number. It is concluded that correlations given in the literature for circular ducts in turbulent flow can give 14% higher dimensionless heat transfer coefficient, Nusselt number, than that of actual hexagonal duct flow.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 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 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".