An experimental investigation of hanging ice dam formation
Notice bibliographique
Résumé
Understanding the formation of hanging ice dams could reduce energy losses, and consequent financial losses, experienced at northern hydroelectric generating stations. Despite several studies that focused on hanging ice dams, a lack of research has been identified in the literature, and no comprehensive study on the factors influencing hanging ice dam formation has been conducted. No previous studies have been conducted to simulate a real world geometric condition that influences the evolution of hanging ice dam. The research presented in this thesis attempts to address this gap. A better comprehension of dynamics beneath a hanging ice dam will help river ice engineers to reduce economic, environmental, and ecological damages. Experimental investigations were conducted in a fixed-bed, with flat (zero sloped) flume in the Hydraulics Research & Testing Facility (HRTF) at the University of Manitoba. Experiments were conducted to investigate the formation of a hanging ice dam and its evolution in terms of areal extent, average thickness, length and maximum width under different flow conditions (e.g., Froude number and ice volume). The effect of various ice concentrations on the same variables was also tested. The whole investigation was divided into two primary conditions; firstly, experiments were conducted to investigate the effects of different Froude numbers on the evolution of hanging ice dam where ice concentration was kept constant. Additional experiments were later conducted to observe the effect of different ice concentrations on hanging ice dam formation keeping the Froude number at a fixed value. A high-resolution GoPro camera was installed above the flume to get top-down photographs at regular intervals during the experiments. Emphasis was also given on how a hanging ice dam develops under a thin ice cover for a certain flow condition. An underwater laser scanner was deployed to observe the approximate shape of hanging ice dams and the changes of maximum thickness. The results indicate that Froude number has a significant impact on the mentioned parameters during hanging ice dam formation. Flow from a narrow channel that outfalls into a wider lake (higher cross sectional area) acts as a surface jet. The evolution and decay of the surface jet are directly related to the streamwise and lateral development of hanging ice dams. Ice concentration also plays an important role in hanging ice dam development. The formation of a hanging ice dam depends on the ice transport capacity and the result of the experiments from this study supports this concept developed by Shen and Wang (1995). It is believed that the results from this experiment will improve our fundamental understanding of hanging ice dam formation, and can be used for validation of subsequent numerical models.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,003 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».