Notice bibliographique
Résumé
"With the rise in popularity of unmanned aerial vehicles (UAVs), there is a need to test these vehicles in a laboratory setting. A Multi-fan wind tunnel (MFWT) facility has been developed and built at McGill for this purpose, and comprises of 81 small fans arranged in a 9-by-9 grid. A MFWT allows the user to create tailored flows with minimal pressure losses, due to the absence of screens and grids. The small fans used in the MFWT also have a fast dynamic response which can be modulated to mimic wind gusts or other naturally occurring wind phenomenon. Before UAVs can be tested in the facility, the flow characteristics of the tunnel must be well documented, with the goal of creating well defined tailored flow fields. The scope of this study is to examine the baseline flow characteristics in the development region of the flow (the region near the wall of fans) and how the inlet conditions of the tunnel can be varied to create different conditions in the flow field. Although dynamic modulation of the wind tunnels fans is possible, this study focuses on the static case where individual fans do not change speed while in operation. In addition to the baseline case with all fans on, different shear ratios of fans configured in a checkerboard pattern have been tested. The fans were wired in an alternating pattern and sent one of two inputs; with signal one and signal two wired to the fans in this alternating pattern, the fan wall resembles a checkerboard. The shear ratio is defined as the ratio of the velocities produced by the two fan signals, Sr = Uhigh/Ulow, with the larger signal as the numerator (shear ratio is always greater to or equal to one). A two-component hot-wire anemometer probe was mounted to a 3D traversing sys- tem inside of the tunnel to obtain the streamwise and transverse velocity components. Shear ratios from 1.00 to 3.50 were investigated, as well as the on-off case; all cases had a bulk flow velocity of 5ms−1. It is found that shear ratios larger than 1.00 produced a noticeable increase in the turbulence intensity, turbulent kinetic energy and integral length scale. At the closest and farthest measured points to the fan wall, an increase of 25.09 % and 14.75 % in turbulence intensity, respectively, was noted as the shear ratio was increased from 1.00 to 3.50 at each location. Critically, turbulence in the vicinity of the fans was found to exhibit non-equilibrium turbulent properties, whereby the non-dimensional dissipation coefficient Cε was found to be approximately inversely proportional to the Taylor-scale based Reynolds number Reλ (as opposed to equilibrium turbulence where Cε = constant). Suggested scalings are proposed for the increase in turbulence intensity, and a similarity with traditional grid turbulence scaling is presented for the decay of the turbulent kinetic energy."@eng
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| 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 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 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 tête enseignante, 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 ».