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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.
21

The mid-depth temperature minimum in B. C. inlets

MacNeill, Margaret Rose January 1974 (has links)
A springtime mid-depth temperature minimum has often been observed in many B.C. inlets. The size and extent of the minimum varies markedly from year to year. This paper examines the temperature minimum more closely,in Bute, Knight and Jervis Inlets. Pickard (1961) suggested that a major factor affecting the size of the temperature minimum layer might be the outflow winds which blow down most B.C. mainland fjords during winter months when the Arctic air mass moves south to cover tne interior of the province. Using Abbotsford Airport as a station representative of outflow (no wind recording devices available in Bute, Knight or Jervis) for Bute, the size of the springtime temperature minimum was compared to the outflow of the previous winter for the period 1954-1973. There seems to be a rough linear relationship between the two. During 1972, 1973 and 1974 monthly cruises were made to Jervis, Bute and Knight - (making it possible to follow winter cooling on a month to month basis. This analysis seems to indicate that in Bute, at least, most of the cooling in the winter occurs during outflow situations. The actual formation of the temperature minimum layer (as shown in the cruises of February and March) appears to be partly caused by down-inlet advection of cold water from the head. It is possible that outflow winds may cause the disturbance which is the origin of the cold advection. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
22

Optimalizace sacího kanálu spalovacího motoru / Optimisation the internal combustion engine intake port

Michal, Tomáš January 2011 (has links)
The thesis is focused on optimizing the inlet port of the modern combustion engine. Of describes the preparation of the 3D model in ProEngineer software environment based on real geometry obtained by reverse engineering system and method ATOS CFD simulates the flow of the inlet manifold. At the end of the work are compared with results of computer simulation of the real test of the meter.
23

Zvýšení účinnosti sacího kanálu zážehového motoru / Increasing Efficiency of Intake Port for SI Engine

Herka, Miroslav January 2012 (has links)
The thesis describes design solutions the inlet port of the modern combustion engine. The thesis describes basic properties of the inlet port and the types of flow. It is focused the experimental measure of the real inlet port engine Husaberg. The results of the experimental measure are compared with results of the simulation in software CFD. Moreover, it describes creation of 3D parametric model in software Pro/Engineer based on the real geometry exquired from software ATOS. At the end of the work are compared with results of the simulation origin geometry inlet port with origin inlet valve with different changes shapes of valve.
24

Comparison of the aeroacoustics of two small-scale supersonic inlets

Miller, Kevin C. 01 November 2008 (has links)
An aerodynamic and acoustic investigation was performed on two small-scale supersonic inlets to determine which inlet would be more suitable for a High Speed Civil Transport (HSCT) aircraft during approach and takeoff flight conditions. The comparison was made between an axisymmetric supersonic P inlet and a bifurcated two-dimensional supersonic inlet. The 1/14 scale model supersonic inlets were used in conjunction with a 4.1 in (10.4 cm) turbofan engine simulator to provide the typical characteristics of a turbofan aircraft engine. A bellmouth was utilized on each inlet to eliminate lip separation commonly associated with airplane engine inlets that are tested under static conditions. Steady state measurements of the aerodynamic flowfield and acoustic farfield were made in order to evaluate the aeroacoustic performance of the inlets. The aerodynamic results show the total pressure recovery of the two inlets to be nearly identical, 99% at the approach condition and 98% at the takeoff condition. At the approach fan speed (60% design speed), there was no appreciable difference in the acoustic performance of either inlet over the entire 0° to 110° farfield measurement sector. The inlet flow field results at the takeoff fan speed (88% design speed), show the average inlet throat Mach number for the P inlet (Mach 0.52) to be approximately 2 times that of the 2D inlet (Mach 0.26). The difference in the throat Mach number is a result of the smaller throughflow area of the P inlet. This reduced area resulted in a “soft choking” of the P inlet which lowered the blade passing tone of the simulator by an average of 9 dB in the forward sector, when compared to the 2D inlet. / Master of Science
25

Archaeomalacological Data and Paleoenvironmental Reconstruction at the Jupiter Inlet I Site (8PB34a), Southeast Florida

Unknown Date (has links)
The Jupiter Inlet I site is situated between the Atlantic coast and the Loxahatchee River in southeast Florida. Although excavations were previously conducted, faunal remains were not systematically collected until recently. Molluscan remains recovered in 2010 are examined to reconstruct past ecological habitats, identify which water bodies were used for extracting resources, and document changes in molluscan species over time. Based upon identifications, only brackish and marine species are represented, indicating that the Loxahatchee River was brackish rather than freshwater during the time of occupation and that the site inhabitants were collecting mollusks from both the lagoon and coastal waters. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
26

Study of the density structure and water flow in the upper 10 m. of a selected region in Bute Inlet, British Columbia.

Johns, Robert Eric January 1968 (has links)
An intense pycnocline at about 4 m. depth existed in Bute Inlet in August, 1967. This corresponded to the largest observed fresh water runoff into the head of the inlet. A major pycnocline above 10 m. depth was not observed in January, 1968, corresponding to small fresh water runoff. Correlating information derived from near-surface transverse and longitudinal sigma-t sections and drift pole plots with wind and tide data, the curvature of the inlet's lateral boundaries was found to influence the disposition of fresh water in any given transverse section. The direction of the surface layer flow was best related to the wind direction except in cases of high runoff when the wind only modulated the speed of outflow. The tide had remarkably little effect. Distinct changes in depth of the pycnocline along inlet were observed.Suggestions for future experiments are presented. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
27

Minimisation of filling time in resin transfer moulding

Semling, M. January 1999 (has links)
No description available.
28

Small-scale biological and physical structure in a tidally mixed fjord

Gaboury, Isabelle. 10 April 2008 (has links)
No description available.
29

Aerodynamic Optimization of Compact Engine Intakes for High Subsonic Speed Turbofans

Udit Vyas (6636125) 10 June 2019 (has links)
<p>Within the gas turbine industry, turbofan engines are widely implemented to enhance engine efficiency, specific thrust, and specific fuel consumption. However, these turbofans have yet to be widely implemented into microgas turbine engines. As turbofans become implemented into smaller engines, the need to design engine intakes for high-speed mission becomes more vital. In this work, a design procedure for compact, highly diffusive engine intakes for high subsonic speed applications is set about. The aerodynamic tradeoffs between cruise and takeoff flights are discussed and methods to enhance takeoff performance without negatively impacting high-speed cruise performance is discussed. Intake performance is integrated into overall engine analysis to help guide future mission analyses. Finally, an experimental model for engine intakes is developed for application to linear wind tunnels; allowing future designers to effectively validate numerical results.<br></p> <p>A multi-objective optimization routine is performed for compact engine intakes at a Mach number of 0.9. This optimization routine yielded a family of related curves that maximize intake diffusive capability and minimize intake pressure losses. Design recommendations to create such optimal intakes are discussed in this work so that future designers do not need to perform an optimization. Due to high diffusion rate of the intake, the intake performance at takeoff suffers greatly (as measured by massflow ingestion). Methods to enhance takeoff performance, from designing a variable geometry intake, to creating slots, to sliding intake components are evaluated and ranked for future designers to get an order of magnitude understanding of the types of massflow enhancements possible. Then, off-design performance of the intake is considered: with different Mach number flights, non-axial flow conditions, various altitudes, and unsteady engine operation considered. These off-design effects are evaluated to generate an intake map across a wide engine operational envelope. This map is then inputted into an engine model to generate a performance map of an engine; which allows for mission planning analysis. Finally, various methods to replicate intake flow physics in a linear wind tunnel are considered. It is shown that replicating diffuser curvature in a linear wind tunnel allows for best replication of flow physics. Additionally, a method to non-dimesnsionalize intake performance for application to a wind tunnel is developed. </p> <p>This work can be utilized by future engine intake designers in a variety of ways. The results shown here can help guide future designers create highly compact diffuser technology, capable of operating across a wide breadth of conditions. Methods to assess intake performance effects on overall engine performance are demonstrated; and an experimental approach to intake analysis is developed.</p>
30

Variabilidade Temporal Da Desembocadura Do Arroio Chuí pela fixação através de molhes

Sfredo, Giuliana Andréia January 2017 (has links)
O Balneário Chuí é uma estreita feição costeira de traçado irregular, assimétrico, adjacente a uma feição de falésias erosivas, que são produtos da Barreira III, desgastada pela ação dos agentes mesológicos atuantes. O Arroio Chuí, por sua vez, é um sistema de drenagem, localizado exclusivamente na zona costeira, que nasce a partir do banhado Canelões, ao sul do banhado do Taim, e segue quase paralelo à costa no sentido sul até o Balneário Barra do Chuí, onde deságua no Oceano Atlântico. A construção dos molhes para a fixação da desembocadura se fez necessária já que, anteriormente à construção dos molhes, iniciada em 1975, o arroio migrava ao longo da linha de costa, provocando, em algumas situações, o total fechamento da barra. Em 1978 foi finalizada a obra que fixou a desembocadura do Arroio Chuí através de molhes, contribuindo para a consolidação do limite territorial entre o Brasil e o Uruguai. Este estudo tem como propósito identificar e descrever a evolução da desembocadura do Arroio Chuí após a sua fixação, a fim de auxiliar no gerenciamento do uso e da ocupação antrópica desta área Para tornar possível a análise da variabilidade temporal, foram utilizadas fotografias aéreas, uma carta topográfica e imagens de satélite de diferentes datas. As imagens passaram por um pré-processamento, foram vetorizadas manualmente e tiveram suas análises realizadas em ambiente SIG. Os resultados mostraram que a obra de fixação através de molhes causou uma variação de posição da desembocadura de 1260 m na direção sul entre 1964, data das imagens mais antigas disponíveis para a região, e 1975, ano do início da construção dos molhes. Este segmento costeiro representou uma perda de 0,16 km² ao Uruguai. Além disso, não foi observada tendência erosiva no balneário brasileiro, como resultado da interrupção do transporte de sedimentos pela deriva litorânea. Espera-se que a análise contribua para a efetuação de um melhor planejamento ambiental e urbano, auxilie ações de gerenciamento costeiro nos balneários Barra do Chuí (BR) e Barra del Chuy (UY) e motive a geração de mais estudos nesta área costeira ainda pouco estudada. / The balneary of Barra do Chuí is a narrow coastal feature with irregular layout, asymmetrical, adjacent to a set of erosive cliffs, which are products of Barrier III, eroded by the action of the mesological agents acting. The Arroio Chuí, in turn, is a drainage system, located exclusively in the coastal zone, which rises from the Canelões wetlands, to the south of the Taim wetlands, and follows almost parallel to the coast in the south direction, marking the border between the balnearies Barra do Chuí (BR) and Barra del Chuy (UY) until draining into the Atlantic Ocean. The construction of the jetties for the fixation of the mouth was necessary because, prior to construction, started in 1975, the rivulet migrated along the coastline, causing, in some situations, the complete closure of the bar. In 1978, the work that established the mouth of the Arroio Chuí was finalized, contributing for the consolidation of the territorial limit between Brazil and Uruguay. This study aims to identify and describe the evolution of the mouth of the Arroio Chuí after its fixation, with the purpose of assisting in the management of the use and the anthropic occupation of this area To make possible the analysis of the temporal variability were used aerial photographs, a topographic chart and satellite images of different dates. The images were pre-processed, manually vectored and analyzed in a GIS environment. The results showed that the work of fixation through jetties caused a position change of the mouth of 1260 m in the south direction between 1964, date of the oldest images available for the region, and 1975, year of the beginning of the jetties construction. This coastal segment represented a 0.16 km² loss to Uruguay. In addition, no erosive trend was observed in the brazilian balneary, as a result of the interruption of sediment transport by the coastal drift. It is expected that the analysis will contribute to better environmental and urban planning, assist coastal management actions in the Chuí (BR) and Barra del Chuy (UY) balnearies and motivate the generation of further studies in this coastal area that has not been studied yet.

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