Evolution of discharge and runner rotation speed along no-load curves of Francis turbines
Bibliographic record
Abstract
Abstract In hydraulic turbines, no-load operation is among the most damaging conditions since unextracted swirl leads to the creation of highly energetic flow structures causing high pressure and strain fluctuations on the turbine components. To date, experimental and numerical studies typically focus on flow characteristics for a specific no-load condition of a specific turbine. However, for a given turbine, a unique no-load condition exists for every single guide vane opening, forming what is called a no-load curve. Few studies describe the evolution of engineering quantities such as discharge and speed along the no-load curve even if those quantities may highlight trends in no-load behavior that can be used to tailor numerical simulations according to specific flow conditions. This paper presents results from a project underway at Andritz Hydro Canada Inc., in collaboration with Université Laval, to analyze the extensive database of experimental no-load tests performed at model scale in order to identify the evolution of discharge and runner rotation speed following the guide vane opening.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".