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Modelação matemática de bueiros. / Mathematical modelling of Culverts.Gaia, Marcos Narvaez 24 June 2014 (has links)
Há tempo que engenheiros vêm procurando amenizar os problemas relacionados aos bueiros. Não só nos escritórios de engenharia, na fase de projetos e cálculos, como também no assentamento final, procurando manter o sistema hidráulico dos bueiros funcionando corretamente. A maioria dos problemas encontrados está associada a mal dimensionamento dos bueiros, dimensionamento insuficiente, ou má avaliação das vazões a serem escoadas. O presente trabalho de pesquisa analisa o escoamento dos bueiros nas obras rodoviárias e ferroviárias de forma a viabilizar seu bom funcionamento. Para tanto, dos nove (9) tipos de escoamentos identificados na atualidade, foram estudados e discutidos dois (2) deles: Escoamento com entrada livre e Escoamento com entrada afogada, ambos com controle na entrada do bueiro. A seção do bueiro escolhida foi a circular, uma vez que a bibliografia específica para este tipo de seção é menos abundante. O desenvolvimento do trabalho foi feito através de modelação matemática buscando-se encontrar o ponto de transição entre os dois (2) tipos de escoamento. Através dos resultados foi possível uma análise mais detalhada, com sugestão de critérios para projetos de bueiros. / There is a long time that engineers has been trying to reduce problems related to culverts. Not only in the engineering offices, in the stage of projects and calculations, as well in the final putting down the culverts, trying to keep the hydraulic system of culverts working well. Most of problems encountered related to culverts are due to weak design conditions, insufficient design condition or bad review of discharges to be flow. This research aims to analyze the culverts flow in roads and rails projects in order to produce a smooth functioning. Therefore, from nine types of flow recently identified there were studied and discussed two of them: Flow with free entry and flow with submerged entry, both cases with inlet control. The cross section of the culvert chosen was the circular, once that the specific literature for this kind of section is less widespread. The work development was done by mathematical modeling where the objective was to find the transition point between these two types of flow. From the results it was possible to develop a detailed analysis and to propose a culvert design criteria.
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Modelação matemática de bueiros. / Mathematical modelling of Culverts.Marcos Narvaez Gaia 24 June 2014 (has links)
Há tempo que engenheiros vêm procurando amenizar os problemas relacionados aos bueiros. Não só nos escritórios de engenharia, na fase de projetos e cálculos, como também no assentamento final, procurando manter o sistema hidráulico dos bueiros funcionando corretamente. A maioria dos problemas encontrados está associada a mal dimensionamento dos bueiros, dimensionamento insuficiente, ou má avaliação das vazões a serem escoadas. O presente trabalho de pesquisa analisa o escoamento dos bueiros nas obras rodoviárias e ferroviárias de forma a viabilizar seu bom funcionamento. Para tanto, dos nove (9) tipos de escoamentos identificados na atualidade, foram estudados e discutidos dois (2) deles: Escoamento com entrada livre e Escoamento com entrada afogada, ambos com controle na entrada do bueiro. A seção do bueiro escolhida foi a circular, uma vez que a bibliografia específica para este tipo de seção é menos abundante. O desenvolvimento do trabalho foi feito através de modelação matemática buscando-se encontrar o ponto de transição entre os dois (2) tipos de escoamento. Através dos resultados foi possível uma análise mais detalhada, com sugestão de critérios para projetos de bueiros. / There is a long time that engineers has been trying to reduce problems related to culverts. Not only in the engineering offices, in the stage of projects and calculations, as well in the final putting down the culverts, trying to keep the hydraulic system of culverts working well. Most of problems encountered related to culverts are due to weak design conditions, insufficient design condition or bad review of discharges to be flow. This research aims to analyze the culverts flow in roads and rails projects in order to produce a smooth functioning. Therefore, from nine types of flow recently identified there were studied and discussed two of them: Flow with free entry and flow with submerged entry, both cases with inlet control. The cross section of the culvert chosen was the circular, once that the specific literature for this kind of section is less widespread. The work development was done by mathematical modeling where the objective was to find the transition point between these two types of flow. From the results it was possible to develop a detailed analysis and to propose a culvert design criteria.
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Application of fluid electrical conductivity logging for fractured rock aquifer characterisation at the University of the Western Cape's Franschhoek and Rawsonville research sitesLasher, Candice January 2011 (has links)
<p>  / Characterisation of fractured rock aquifers is important when dealing with groundwater protection and management. Fractures are often good conduits for water and contaminants, leading to high flow velocities and the fast spread of contaminants in these aquifers. A cost effective methodology is required for the characterisation of the role of individual fractures contributing to flow to boreholes in fractured rock aquifers. Literature shows that some of the conventional methods used to characterise hydraulic properties in fractured rock aquifers are expensive, complicated, time consuming and are associated with some disadvantages such as over-or under- estimations of flow rates. iii This thesis evaluates the use of Fluid Electrical Conductivity (FEC) logging in fractured rock aquifers. This FEC data are compared to various traditional methods used to determine aquifer hydraulic properties applied at the Franschhoek and Rawsonville research sites. Both these sites were drilled into the fractured rock Table Mountain Group (TMG) Aquifer, forming one of the major aquifers in South Africa.</p>
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Application of fluid electrical conductivity logging for fractured rock aquifer characterisation at the University of the Western Cape's Franschhoek and Rawsonville research sitesLasher, Candice January 2011 (has links)
<p>  / Characterisation of fractured rock aquifers is important when dealing with groundwater protection and management. Fractures are often good conduits for water and contaminants, leading to high flow velocities and the fast spread of contaminants in these aquifers. A cost effective methodology is required for the characterisation of the role of individual fractures contributing to flow to boreholes in fractured rock aquifers. Literature shows that some of the conventional methods used to characterise hydraulic properties in fractured rock aquifers are expensive, complicated, time consuming and are associated with some disadvantages such as over-or under- estimations of flow rates. iii This thesis evaluates the use of Fluid Electrical Conductivity (FEC) logging in fractured rock aquifers. This FEC data are compared to various traditional methods used to determine aquifer hydraulic properties applied at the Franschhoek and Rawsonville research sites. Both these sites were drilled into the fractured rock Table Mountain Group (TMG) Aquifer, forming one of the major aquifers in South Africa.</p>
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Stanovení ztrát při nestacionárním proudění kapaliny v trubici / Hydraulic losses during unsteady flow of liquid in a pipeSvoboda, Jakub January 2011 (has links)
This thesis is focused on solving hydraulic losses during unsteady flow of liquid in pipe for both laminar and turbulent flow in smooth pipes. Radial viscosity distribution is assumed to be the same as for steady flow. Viscosity distribution is derived from velocity profile, which is mathematically described with suitably chosen function. Laplace images of unsteady velocity profile and mean velocity in cross-section are derived depending on pressure difference. Loss coefficient is derived and on base of transfer matrix method, self-numbers are calculated. Self-numbers represent attenuation and own frequency. Self-numbers are compared to values from software called “F-ACHAR” and loss coefficient is compared to the one for quasi-steady method.
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Potentialities of Unmanned Aerial Vehicles in Hydraulic Modelling : Drone remote sensing through photogrammetry for 1D flow numerical modellingReali, Andrea January 2018 (has links)
In civil and environmental engineering numerous are the applications that require prior collection of data on the ground. When it comes to hydraulic modelling, valuable topographic and morphology features of the region are one of the most useful of them, yet often unavailable, expensive or difficult to obtain. In the last few years UAVs entered the scene of remote sensing tools used to deliver such information and their applications connected to various photo-analysis techniques have been tested in specific engineering fields, with promising results. The content of this thesis aims contribute to the growing literature on the topic, assessing the potentialities of UAV and SfM photogrammetry analysis in developing terrain elevation models to be used as input data for numerical flood modelling. This thesis covered all phases of the engineering process, from the survey to the implementation of a 1D hydraulic model based on the photogrammetry derived topography The area chosen for the study was the Limpopo river. The challenging environment of the Mozambican inland showed the great advantages of this technology, which allowed a precise and fast survey easily overcoming risks and difficulties. The test on the field was also useful to expose the current limits of the drone tool in its high susceptibility to weather conditions, wind and temperatures and the restricted battery capacity which did not allow flight longer than 20 minutes. The subsequent photogrammetry analysis showed a high degree of dependency on a number of ground control points and the need of laborious post-processing manipulations in order to obtain a reliable DEM and avoid the insurgence of dooming effects. It revealed, this way, the importance of understanding the drone and the photogrammetry software as a single instrument to deliver a quality DEM and consequently the importance of planning a survey photogrammetry-oriented by the adoption of specific precautions. Nevertheless, the DEM we produced presented a degree of spatial resolution comparable to the one high precision topography sources. Finally, considering four different topography sources (SRTM DEM 30 m, lidar DEM 1 m, drone DEM 0.6 m, total station&RTK bathymetric cross sections o.5 m) the relationship between spatial accuracy and water depth estimation was tested through 1D, steady flow models on HECRAS. The performances of each model were expressed in terms of mean absolute error (MAE) in water depth estimations of the considered model compared to the one based on the bathymetric cross-sections. The result confirmed the potentialities of the drone for hydraulic engineering applications, with MAE differences between lidar, bathymetry and drone included within 1 m. The calibration of SRTM, Lidar and Drone based models to the bathymetry one demonstrated the relationship between geometry detail and roughness of the cross-sections, with a global improvement in the MAE, but more pronounced for the coarse geometry of SRTM.
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Posouzení vybraných metrologických charakteristik měřidel bodové rychlosti vodního proudu využívající elektromagnetického principu měření / Metrological characteristics of current velocity meters using the electromagnetic principle of measurementVítů, Martin Unknown Date (has links)
This master’s thesis deals with the assesment of directional sensivity and accuracy of current stream velocity using electromagnetic induction meters in circumstances simulating the real measurement profiles condictions. The theoretical part of the thesis describes the issue of streamflow measurement in open channels and determination of the relevant measurement uncertainties. It also includes description of the hydraulic circuit and the subject current velocity meters. The experimental part of the thesis focuses on the effect of turbulence on the value and accuracy of measured velocity and directional sensivity of electromagnetic induction meters of current velocity. The results are compared with parameters given by manufacturers, research by other authors and with the metrological characteristics of hydrometric propellers, which are commonly used for streamflow measurement in open channels.
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