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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.
1

An investigation of the decay of isotropic turbulence behind a square mesh grid in a water tunnel

Dubose, James Rembert 08 1900 (has links)
No description available.
2

Head loss in symmetrical bifurcations

Ahmed, Sirajuddin January 1965 (has links)
Five symmetrical wye branches of conventional and spherical types were tested for hydraulic losses under symmetrical and unsymmetrical flow conditions. Results are presented graphically. A wide variation in loss factor was observed depending on the type of wye and on flow condition. For a given wye the minimum wye loss coefficient does not necessarily occur under conditions of symmetrical flow. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
3

Velocity field measurements in the near wake of a parachute canopy

Desabrais, Kenneth J. January 2002 (has links)
Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: parachute shedding characteristics; near wake evolution; parachute inflation; canopy breathing; velocity field measurements. Includes bibliographical references (p. 126-131).
4

Visualização experimental de escoamentos no interior de canais munidos de protuberâncias parietais

Bassan, Rodrigo Augusto [UNESP] 26 August 2011 (has links) (PDF)
Made available in DSpace on 2016-03-07T19:20:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-26. Added 1 bitstream(s) on 2016-03-07T19:23:51Z : No. of bitstreams: 1 000859557.pdf: 4186035 bytes, checksum: 8bdc39e13acd7f3473cf85fc408591fa (MD5) / Neste trabalho realiza-se um estudo do escoamento no interior de um canal com protuberâncias parietais para números de Reynolds menores que 103. Os ensaios foram conduzidos em um túnel hidrodinâmico vertical. Perfis de velocidade na seção de testes, assim como a intensidade turbulenta do túnel e emissões de vórtices, foram adquiridos por meio da anemometria de fio/filme quente. Técnicas de visualização de escoamentos, também, foram empregadas em diferentes circunstâncias, com três objetivos fundamentais: como ferramenta de análise qualitativa, na identificação de padrões de escoamento; como mecanismo de apoio à realização de medidas experimentais, para auxiliar no correto posicionamento de sondas anemométricas; e, finalmente, como instrumento complementar de análise, para facilitar a interpretação de resultados. Em todos os casos o escoamento foi tratado estritamente bidimensional. Outro fator importante deste trabalho refere-se a reconstrução do túnel hidrodinâmico vertical, o qual situa-se no Laboratório de Visualização de Escoamentos do Departamento de Engenharia Mecânica da UNESP - campus de Ilha Solteira; que com grande empenho dos Professores Edson Del Rio Vieira, Sergio Said Mansur, Técnicos do laboratório e com uma pequena contribuição de minha parte pode-se finalizar esse projeto / In the present work is accomplished a study of the flow within a channel with parietal 3 protuberances for Reynolds numbers less than 10 . The tests were conducted in a hydrodynamic tunnel vertical. Velocity profiles in the test section, as well as the turbulent intensity of the tunnel, vortex emissions were acquired through anemometry wire / hot film. Flow visualization techniques were employed as a tool for qualitative analysis, in the identification of flow patterns, as qualitative analytical tool to identify flow patterns; as a mechanism to support the implementation of experimental measurements, to assist in the correct positioning of airspeed probes; and finally as an additional tool of analysis, to facilitate interpretation of results. In every case the disposal was treated dimensional strictly. Another important factor of this work refers to the reconstruction of vertical hydrodynamic tunnel, which is located in the Flow View Laboratory, Department of Mechanical Engineering of UNESP - campus of Single Island; that with great commitment of Teachers Edson Vieira Del Rio, Sergio Said Mansur, lab technicians and a small contribution from me you can finish this project
5

Visualização experimental de escoamentos no interior de canais munidos de protuberâncias parietais /

Bassan, Rodrigo Augusto. January 2015 (has links)
Orientador: Sérgio Said Mansur / Co-orientador: Edson Del Rio Vieira / Banca: André Luiz Seixlack / Banca: Odenir de Almeida / Resumo: Neste trabalho realiza-se um estudo do escoamento no interior de um canal com protuberâncias parietais para números de Reynolds menores que 103. Os ensaios foram conduzidos em um túnel hidrodinâmico vertical. Perfis de velocidade na seção de testes, assim como a intensidade turbulenta do túnel e emissões de vórtices, foram adquiridos por meio da anemometria de fio/filme quente. Técnicas de visualização de escoamentos, também, foram empregadas em diferentes circunstâncias, com três objetivos fundamentais: como ferramenta de análise qualitativa, na identificação de padrões de escoamento; como mecanismo de apoio à realização de medidas experimentais, para auxiliar no correto posicionamento de sondas anemométricas; e, finalmente, como instrumento complementar de análise, para facilitar a interpretação de resultados. Em todos os casos o escoamento foi tratado estritamente bidimensional. Outro fator importante deste trabalho refere-se a reconstrução do túnel hidrodinâmico vertical, o qual situa-se no Laboratório de Visualização de Escoamentos do Departamento de Engenharia Mecânica da UNESP - campus de Ilha Solteira; que com grande empenho dos Professores Edson Del Rio Vieira, Sergio Said Mansur, Técnicos do laboratório e com uma pequena contribuição de minha parte pode-se finalizar esse projeto / Abstract: In the present work is accomplished a study of the flow within a channel with parietal 3 protuberances for Reynolds numbers less than 10 . The tests were conducted in a hydrodynamic tunnel vertical. Velocity profiles in the test section, as well as the turbulent intensity of the tunnel, vortex emissions were acquired through anemometry wire / hot film. Flow visualization techniques were employed as a tool for qualitative analysis, in the identification of flow patterns, as qualitative analytical tool to identify flow patterns; as a mechanism to support the implementation of experimental measurements, to assist in the correct positioning of airspeed probes; and finally as an additional tool of analysis, to facilitate interpretation of results. In every case the disposal was treated dimensional strictly. Another important factor of this work refers to the reconstruction of vertical hydrodynamic tunnel, which is located in the Flow View Laboratory, Department of Mechanical Engineering of UNESP - campus of Single Island; that with great commitment of Teachers Edson Vieira Del Rio, Sergio Said Mansur, lab technicians and a small contribution from me you can finish this project / Mestre
6

A study of the mechanism for vortex breakdown and some measures for its control

Jones, Michael Charles, 1971- January 2002 (has links)
Abstract not available
7

Development of a five-component strain-gauge balance for the DSTO water tunnel

Erm, Lincoln P. Ferrarotto, Phil. January 2009 (has links) (PDF)
Mode of access: Internet via World Wide Web. Available at http://hdl.handle.net/1947/10033. / "November 2009". Available on the DSTO website as at DSTO at :http://dspace.dsto.defence.gov.au/dspace/bitstream/1947/10033/1/DSTO-GD-0597%20PR.pdf
8

Steps as hydraulic roughness elements in segmentally lined tunnels

Bester, J. W. January 2002 (has links)
Thesis (MEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Segmentally lined tunnels are increasingly being built to transfer water from one water scheme to another. The segments that line such tunnels are often in the form of pre-cast concrete sections, which are placed around the perimeter of the tunnel. As these tunnels are very expensive to construct, it is imperative that their hydraulic capacities can be calculated accurately. Even a slight variation in the design diameter has a significant effect on the cost of the tunnel. Due to the construction method involved, alternative segments are not always properly aligned. This creates roughness elements in the tunnel commonly known as steps. These steps occur randomly and vary in size. Since the steps lead to increased roughness and thus decrease the hydraulic capacity of the tunnel, it is essential that this effect be allowed for in the design of the tunnel. A hydraulic model was used to determine the contribution of steps to the hydraulic roughness, according to step size and frequency of steps. / AFRIKAANSE OPSOMMING: Tonnels word al hoe meer gebou om water tussen waterskemas te vervoer. Die voering van sulke tunnels word dikwels saamgestel uit voorafvervaardigde beton panele wat geplaas word om 'n huls langs die omtrek van die tonnel te vorm. Aangesien hierdie tonnels geweldig duur is om te bou, is dit uiters noodsaaklik dat die hidrouliese kapasiteit van 'n tonnel akkuraat bereken kan word. 'n Klein variasie in die diameter van die tonnel het 'n betekenisvolle effek op die koste daarvan. Die konstruksiemetode van sulke tonnels veroorsaak dat opeenvolgende panele nie altyd presies oplyn nie. Sulke afwykings in die belyning van die tonnelpanele veroorsaak klein trappies, wat bydra tot die ruheid in die tonne I en sodoende die kapasiteit daarvan laat afneem. Die afwykings varieer in grootte en kom in geen spesifieke patroon voor nie. 'n Modelstudie is uitgevoer om die bydrae wat die afwykings in the belyning van die opeenvolgende ringe tot die hidrouliese weerstand maak, te bepaal.
9

Flow visualization study of the inlet vortex phenomenon

De Siervi, Francesca January 1981 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Francesca De Siervi. / M.S.
10

Velocity Field Measurements in the Near Wake of a Parachute Canopy

Desabrais, Kenneth J. 26 April 2002 (has links)
The velocity field in the wake of a small scale flexible parachute canopy was measured using two-dimensional particle image velocimetry. The experiments were performed in a water tunnel with the Reynolds number ranging from 3.0-6.0 x 104. Both a fully inflated canopy and the inflation phase were investigated in a constant freestream (i.e. an infinite mass condition). The fully inflated canopy experienced a cyclic“breathing" which corresponded to the shedding of a vortex ring from the canopy. The normalized breathing frequency had a value of 0.56 +/- 0.03. The investigation of the canopy inflation showed that during the early stages of the inflation, the boundary layer on the canopy surface remains attached to the canopy while the canopy diameter increases substantially. The boundary layer begins to separate near the apex region when the diameter is ~68% of the fully inflated diameter. The separation point then progresses upstream from the canopy apex region toward the canopy skirt. During this time period, the force rapidly increases to its maximum value while the separation point of the boundary layer moves upstream towards the skirt. The force then declines rapidly and the separated boundary layer rolls-up into a large vortex ring near the canopy skirt. At the same time, the canopy is drawn into an over-expanded state after which the cyclic breathing initiates. The unsteady potential force was estimated from the rate of change of the canopy volume. It contributed no more than 10% of the peak opening force and was only significant during the early stages of inflation. The majority of the opening force was the result of the time rate of change of the fluid impulse. It accounts for approximately 60% of the peak opening force. This result shows that the formation of the viscous wake is the primary factor in the peak drag force of the canopy.

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