A Re-examination of Power Coefficient as a Measure of Performance for Horizontal Axis Wind Turbines
Bibliographic record
Abstract
Linear momentum theory as applied to horizontal axis wind turbines (HAWTs) provides perhaps the most useful basis for understanding their operation.In particular, the theoretically derived expression for power coefficient represents a convenient measure of performance, as well as provides insight into optimal operating conditions.The typical interpretation of power factor as an energy conversion efficiency, however, especially in the context of converting the "power in the wind" to a power output, has several conceptual difficulties.In this paper it is argued that the energy efficiency interpretation of power coefficient can be misleading, potentially leading to misinterpretation of performance of different wind turbine designs.Instead, an interpretation of power coefficient as the "relative capture area" of a wind turbine is suggested, analogous to the relative capture width parameter for ocean wave energy conversion devices.Such an interpretation gives a more physically coherent picture of wind turbine performance and provides a more pragmatic measure of performance, one that can also be applied to other wind machine designs.
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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 | 0.006 | 0.026 |
| Meta-epidemiology (narrow) | 0.002 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.003 |
| Science and technology studies | 0.001 | 0.006 |
| Scholarly communication | 0.005 | 0.010 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.007 |
| Insufficient payload (model declined to judge) | 0.003 | 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".