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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.
171

Jämförande studie av två parameterskattningsmetoder i ett grundvattenmagasin / Comparative study of two parameter estimation methods in a groundwater aquifer

Eriksson, Stefan January 2013 (has links)
Syfte med examensarbetet har varit att upprätta en grundvattenmodell överEnköpingsåsen med hjälp av programvaran MODFLOW för att därefter försöka skattagrundvattenmagasinets parametrar. Parameterskattningen utfördes med detmodelloberoende programmet PEST. Parallellt med detta gjordes även enpumptestutvärdering av dessa parametrar där typkurvor passades till en tidigare utfördprovpumpning av akviferen. Därefter jämfördes dessa båda metoder. Vidare utfördesäven en känslighetsanalys av grundvattenmodellen i MODFLOW för att försökalokalisera nya undersökningsplatser.Grundvattenmodellen uppfördes över Enköpingsåsen i och kring Enköping. Där är åsenlokaliserad i nord sydlig riktning och strax söder om Enköpings centrala delar korsasåsen av Enköpingsån. Det råder osäkerhet angående grundvattenmagasinetsvattenbalans och var åsen får sitt tillskott av vatten ifrån. Enköpingsåsen fungerar somhuvudvattentäkt i Enköpings stad vilket gör att detta har ansetts viktigt att utreda.Grundvattenmodellen byggdes upp genom att främst använda redan insamlad data frångeotekniska, geofysiska och hydrogeologiska undersökningar utförda i området samtdata från SGU och SMHI. Därifrån togs data om områdets uppbyggnad och struktursamt dess yttre betingelser som till exempel nederbörd och Mälarens vattenstånd för attskapa en numerisk modell i MODFLOW.Resultaten visar på ett överensstämmande resultat mellan parameterskattningen gjord iMODFLOW och pumptestutvärderingen. Vidare tyder resultaten i MODFLOW på attde största osäkerheterna i modellen ligger kring Enköpingsån och är då beroende av omvattnet tillförs från grundvattenmagasinets laterala delar eller från Enköpingsån.Känslighetsanalysen tyder även på att för ytterligare undersökningar av åsenshydrogeologiska betingelser bör fokus ligga på förhållandena i Enköpingsåns sedimentoch dess genomsläpplighet. / The purpose of this thesis is to establish a groundwater model of the Enköping eskerusing MODFLOW simulation and then estimate groundwater parameters with themodel-independent program PEST. In parallel, a pump test evaluation of theseparameters where type curves are fitted to a previously performed pump test of theaquifer is done to estimate the aquifer parameters. Eventually, these two methods arecompared. Furthermore, a sensitivity analysis of the groundwater model is performed totry to locate additional measurement points.The groundwater model was built for the Enköping esker in and around Enköping. Theesker is located in the north-south direction and just south of Enköpings central partswhere Enköpingsån crosses the esker. There is uncertainty regarding the water balanceof the aquifer and where the esker recharges its water from. Enköping esker serves asthe main water source in Enköping city and this is why it is considered important toinvestigate.The groundwater model was constructed primarily by using already collected data fromgeotechnical, geophysical and hydrogeological studies conducted in the area as well asdata from the SGU and SMHI. The data on the area's composition and structure as wellas its external conditions is taken to create a numerical model in MODFLOW.The results show consistent outcomes between parameter estimates made withMODFLOW/PEST and the pump test evaluation.The results made with MODFLOW makes it possible to do further analysis. Resultsshow large model uncertainties around Enköpingsån and the esker is dependent onwater supplied from either the groundwater aquifer’s lateral parts or Enköpingsån. Thesensitivity analysis also suggests that further studies of the hydrogeological conditionsshould be concentrated to Enköpingsån’s sediments and its water penetration capacity.
172

Studie protipovodňových opatření v lokalitě Maloměřice na Svitavě v km 8,085 – 10,950 / Feasibility study of the flood protection measures in the locality of Maloměřice at the Svitava river at km 8,085 – 10,950

Kavalírová, Anna January 2016 (has links)
This master’s thesis deals with exploring present conditions in Maloměřice-Brno during floods which is followed by design of antiflood protective structures. Research uses coupled 1D/2D numerical model for flood discharges Q1, Q5, Q20 and Q100 computing. In the last step maps of hazard and draw documentation were made.
173

Hydraulic properties of the table mountain group (TMG) aquifers

Titus, Rian January 2008 (has links)
Philosophiae Doctor - PhD / Research findings in current study provide a new insight into the fractured rock aquifers in the TMG area. Some of the results will have wide implications on the groundwater management and forms a solid basis the further study of the TMG aquifers.
174

Hydraulic properties of the Table Mountain Group (TMG) aquifers

Lin, Lixiang January 2008 (has links)
Philosophiae Doctor - PhD / Research findings in current study provide a new insight into the fractured rock aquifers in the TMG area. Some of the results will have wide implications on the groundwater management and forms a solid basis the further study of the TMG aquifers.
175

Mise en évidence et simulation de l’endommagement des revêtements de carbone amorphe pour application moteur à combustion interne / DLC damage identification and simulation for internal combustion engine application

Pagnoux, Geoffrey 23 September 2015 (has links)
L'exploitation de revêtements micrométriques à base de carbone amorphe (les DLC) tend à se généraliser au sein des constructeurs automobiles afin d'améliorer le rendement des moteurs à combustion interne en réduisant les pertes mécaniques par frottement. Si ces revêtements exhibent généralement d'excellentes propriétés tribologiques et de très faibles taux d'usure, leur utilisation au sein des moteurs à combustion interne révèle que, soumis à des sollicitations complexes, de nombreux modes de dégradations sont observables. La propagation prématurée de ces dégradations sur l'intégralité des surfaces revêtues constitue un risque à maîtriser pour garantir la fonction des revêtements dans le temps. Cette maîtrise implique d'une part de connaître et de comprendre les mécanismes de dégradations probables des DLC appliqués aux composants du moteur et d'autre part de disposer d'outils de simulation de leur durée de vie, exploitables pour optimiser les systèmes tribologiques au plus tôt de leur conception. Les travaux présentés dans cette thèse ont été guidés par ces objectifs et rassemblent des expertises de composants revêtus, des développements d'analyses numériques, de protocoles d'essais simplifiés et des recherches de couplages entre modes de dégradations. Autant d'éléments qui permettent de répondre en partie aux questions initialement posées et de proposer, au final, un outil de simulation de durée de vie des DLC adapté aux applications moteur à combustion interne / The use of micrometric diamond-like carbon coatings (named DLC) are becoming widely used by automotive manufacturers in order to improve the efficiency of internal combustion engines by reducing the mechanical friction losses. Although DLC coatings generally exhibit excellent tribological properties and very low wear rates, their use in internal combustion engines shows that, subject to complex loadings, many degradation modes are observable. Untimely propagation of these latter upon the entire coated surfaces is a risk to control in order to guarantee the coating function over time. From one hand, this control implies to know and to understand all DLC degradation mechanisms when applied to engine components. On the other hand, it is necessary to possess lifetime simulation tools that can be used to optimize tribological systems in their early design. The work presented in this thesis has been guided by these goals and gathers experimental analyses of DLC-coated components, numerical analyzes, simplified testing protocols and coupling analyses of degradation processes. All these topics finally lead to the definition of a lifetime simulation tool adapted to DLC coated internal combustion engine applications
176

FEM model ultrazvukového senzoru hladiny oleje / Numerical model of ultrasonic oil level sensor

Chutný, Pavel January 2017 (has links)
This master’s thesis verifies physical principle of ultrasound in fluids by numerical model. At first, ultrasound study is ment. In second theoretic part, diferent kind of motor oils are described. Next, equations for numerical simulation are presented. In practical part, numerical model of level sensor is examined in well-knowed fluids (water, air). Results of laboratory measurement on topic of ultrasound velocity in oil dependent on temperature are aplicated on numerical model of sensor and optimalized.
177

Hydrodynamický model soutokové oblasti Svitavy a Svratky / Hydrodynamic model in the area of the confluence of the rivers Svitava and Svratka

Halaška, Ondřej January 2018 (has links)
Master's thesis deals with present state assessment of flood hazard on rivers Svitava and Svratka in the southern part of Brno. Flood discharges Q5, Q20, Q100 and Q100N were solved using coupled 1D/2D numerical model. All results were evaluated as maps of hazard.
178

Numerické modelování proudění v bezpečnostním přelivu / Numerical modeling of flow in spilway

Svoboda, Jiří Unknown Date (has links)
The goal of the diploma thesis is the numerical modelling of flow in planned spillway of the Boskovice dam. In the introduction of this diploma thesis are described and divided basic spillways according to their types and profiles. There are also mentioned emergency spillways. Then the thesis introduces the description of calculation of overflow quantity, the description of mathematic modelling and used turbulent models. The next part is concerned with the technical description of the Boskovice dam, the creation of virtual 3D model of spillway and spillway chute in the AutoCAD 2020 software and concerned with the control and revision of model in the Blender software. In the end of the thesis are mentioned results of numeric modelling of flow gained from the Flow-3D software and the comparison of results with the research of hydraulic model implemented at Water structures institute of Faculty of Civil Engineering of BUT.
179

Optimalizace výfukového potrubí přeplňovaného zážehového motoru / Optimalization of Exhaust Manifold for SI Turbo Engine

Andrys, Michal January 2010 (has links)
Abstract Michal ANDRYS Optimalization of Exhaust Manifold for SI Turbo Engine DP, IAE, 2010, 67 pp., 75 fig. The Diploma thesis is oriented on the design of exhaust manifold for si turbo engine. It specifies suitable manifold connection to the separate branches, folowed by CFD analysis.
180

Studie protipovodňových opatření v lokalitách Husovice a Židenice na Svitavě v km 6,000 – 9,000 / Feasibility study of the flood protection measures in the localities of Husovice and Židenice at the Svitava river at km 6,000 – 9,000

Hanzlíková, Zuzana January 2016 (has links)
Diploma thesis deals with a suggestion of flood protection measures on the Svitava river in km 6,000 – 9,000. Solved locality is found in Brno, particularly in city parts of Husovice and Židenice. Thanks to used joined 1D and 2D model were made hydraulic calculations for peak water stages Q1, Q5, Q20 a Q100. The outputs of hydraulic calculations were used afterwards for creation of maps of flood danger and drawing documentation of flood protection measures.

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