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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Acceleration of coherent structures in free shear layer

周健強, Chow, Kin-keung. January 1999 (has links)
published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy
52

Investigation of a round jet into a counterflow

陳孝章, Chan, Hau-cheung. January 1998 (has links)
published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy
53

Mixing of a rosette buoyant jet group

Lai, Chun-hin, Adrian., 黎駿軒. January 2009 (has links)
published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy
54

Mixing of inclined dense jets

Lai, Chung-kei, Chris., 黎頌基. January 2009 (has links)
published_or_final_version / Civil Engineering / Master / Master of Philosophy
55

Supersonic and subsonic radial jets

Ho, Y. K. January 1987 (has links)
No description available.
56

Etude expérimentale de jets libres, compressibles ou en présence d'un obstacle / Experimental study of free jets and jets with compressible effects or impinging an obstacle

Dubois, Julien 14 June 2010 (has links)
L’objectif de ces travaux est d’étudier expérimentalement la dispersion d’hydrogène pour évaluer l’impact des fuites chroniques ou accidentelles qui peuvent intervenir en milieu libre ou encombré, à faible ou à forte pression, sur un véhicule fonctionnant avec une pile à combustible. Les fuites étudiées sont assimilées à des jets verticaux, turbulents, axisymétriques, à densité variable, et issus d’orifices cylindriques de 1 à 3 mm de diamètre. Un banc expérimental a été conçu pour étudier ces fuites : l’hydrogène a été remplacé par de l’hélium pour des raisons de sécurité. Il résiste à une pression de 200 bars et permet de positionner un obstacle dans le jet. La technique BOS (Background Oriented Schlieren) a été adaptée aux jets millimétriques et à la présence d’un obstacle. Un soin particulier à été apporté à la mise en place de cette technique. Les résultats obtenus sont en accord avec ceux de la littérature quand il en existe. De nouvelles lois de similitude sont proposées, plus représentatives de la physique des jets : libres subsoniques, libres sousdétendus, et subsoniques en présence d’un obstacle (sphère). À partir de l’analyse de la structure compressible des jets sous-détendus, de nouvelles lois sont aussi proposées pour estimer la position et le diamètre du disque de Mach puis la longueur du cône potentiel. Enfin, deux lois d’estimation du volume et de la masse inflammables de jets libres d’hydrogène sont proposées : elles sont fonction du débit massique de la fuite. / The aim of this work is to experimentally investigate the hydrogen dispersion to evaluate the impact of chronic or accidental leaks that may occur in a free or in a congested environment, from a low or a high pressure tank, on a fuel cell vehicle. The leaks are assimilated to vertical turbulent and axisymmetric jets with variable density. They are issued from cylindrical orifices from 1 to 3 mm diameter. An experimental set-up was designed to investigate the leaks : hydrogen has been replaced by helium for safety reasons. It supports a 200 bar pressure and allows to position an obstacle in the jet flow. The BOS (Background Oriented Schlieren) technique has been adapted to millimeter jets and to the presence of an obstacle. Particular attention has been given to the development of this technique. The results show good agrement with the available litterature data.New similarity laws are proposed, more representative of the flows of : subsonic free jets, under-expanded free jets, and subsonic impinging (a sphere) jets. From the structure analysis of compressible under-expanded free jets, new relations are proposed to estimate the Mach disk position and diameter as well as the potential core length. Finally, two new laws are found from the analysis of flammable volume and flammable mass : they are based on the leak mass flow rate.
57

Mathematical analysis of the characteristics of axially symmetric downward jet

Chiu, Huei-Huang January 1956 (has links)
No description available.
58

Effect of core shapes on the flow of jets from unit heater outlets

Attri, Narinder Singh January 1958 (has links)
No description available.
59

A study of round, line-like and meandering turbulent fountains

Debugne, Antoine Louis René January 2018 (has links)
The dynamics of different classes of turbulent and miscible fountains are stud- ied: from classic axisymmetric fountains issuing from round sources, to confined fountains propagating in a quasi-two-dimensional environment, to line fountains which form when release conditions are approximately two-dimensional at the source. Each class is characterised by distinct dynamical behaviour, which this the- sis analyses both through theoretical arguments and experimental measurements. A model for the entrainment of ambient fluid into a fluctuating fountain top is developed and implemented into a first complete description for round fountains. The solutions of the resulting 'three-region-model' lie in improved agreement with available data and, uniquely, do not diverge near the top of the fountain. Next, con- fined fountains (unexplored to date) are classified into four flow regimes and their behaviour collapsed according to a single governing parameter that captures the severity of confinement. Finally, new experiments on line foutains shed light on the quasi-steady structure of these flows, revealing (and motivating) a strong con- nection between their motion in the vertical and lateral planes. Round, confined and line fountains are then contrasted in the conclusions, where we reflect on what is required to progress towards a unified theory of turbulent fountains.
60

Experimental study of turbulent buoyant surface jets

Vanvari, Madanlal R. January 1974 (has links)
No description available.

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