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Assessment effects substandard tributaries flowing a proportion on Q/h characteristics thin-plate weir with a rectangular cutout
Šmidrkalová, Nina ; Šafář, Robert (referee) ; Žoužela, Michal (advisor)
This master´s thesis deals with the problem of measuring flow, especially using the method of Q/H characteristics. It describes the thin-plate weir and mentions specific channels. The master´s thesis suggests options of monitoring flow capacity in fixed proffiles with free surface. The master´s thesis also includes an experiment, which is focused on simulation of substandard tributary flowing proportions before weirs for determining their effect on Q/H characteristcs. The experiment is carried out on a thin-plate weir with a rectangular notch at the Department of Water Structures at the Faculty of Civil Engeneering in Brno. Another part of the master´s thesis is data processing to get an idea about the impact of the phenomenon in real applications. Finally, options are recommended for follow-up research.
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The determination of minimal countercurrent distance of the water surface sensor from the thin-plate V-notch weir.
Kopečná, Monika ; Zubík, Pavel (referee) ; Žoužela, Michal (advisor)
This thesis clarifies the issue of the measuring flows with the help of capacity measurement systems using Q/h characteristics and also describes measuring techniques for determining the water surface level. The various types of measuring weirs and their Q/h characteristics are described in detail. It also mentions the position of the installation of the sensor. The main task is to find a practical minimal countercurrent distance of the water surface sensors used in practice for use with a V-notch weir in the form of experimental measurements in the water management research laboratory at the Department of Water Structures Faculty of Civil Engineering in Brno. The weirs used for this experiment had top angle cutouts of 90°, 53°8´ and 28°4´. The obtained data is evaluated and subsequently the minimal countercurrent distance of the water surface sensor is determined. The thesis also includes recommendations for further research.
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The hydraulic modelling research of specific shutter intended for determination of water flow in circular profiles with free surface
Heřmanová, Lenka ; Šafář, Robert (referee) ; Žoužela, Michal (advisor)
The main outcome of this Thesis is a set of Q / h characteristic that was obtained extensive hydraulic model research measuring plate designed for the determination of water flow in circular profiles. The final Q / h characteristic are functions of angle and vertical cut remoteness of the top slot from the bottom of the measurement aperture. Part of the output is an overview of the expected values of uncertainties of measurement in practical use in a specific aperture in sewers and evaluation of impacts involved in determining the overall uncertainty of the flow. The performed hydraulic modeling research is therefore possible to determine Q / h and characteristics for circular sections of larger diameter and to determine their uncertainties when using specific plate. For the design and shape measuring plate of the profile with larger average output is part of a supplement for quick design of specific screens.
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Determination of Small Discharges of Water by Triangular Notch Thin-Plate Weirs
Pospíšilík, Šimon ; Havlík,, Aleš (referee) ; Šoltézs, Andrej (referee) ; Zachoval, Zbyněk (advisor)
The work deals with the determination of relatively small discharges of clear water using a thin-plate weir with a triangular notch. Based on a detailed search of contemporary knowledge, the scope of the necessary experimental research was defined in the range of parameters practically suitable for the determination of small discharges. It was about extending the range of notch angles by small angles, defining the minimum weir height depending on the notch angle, determining the influence of the minimum value of the weir height and the width of the approach channel on the discharge and investigating the effect of water temperature on the discharge. Extensive experimental research was carried out involving changes in the notch angle, head, weir height, approach channel width and water temperature. The uncertainties of the measured data were quantified. By analysing possible ways of expressing small water discharges using thin-plated weirs with a triangular notch and based on the measured data, a new equation for determining water discharges was recommended as the most suitable. The new equation combines the Kindsvater-Shen approach, which captures the cumulative effects of viscosity and surface tension, and the approach of covering the effect of the relative width of the approach channel by introducing a new coefficient. By evaluating the measured data, the effective discharge coefficient, the relative width of the approach channel coefficient, the effective head and the limit head were determined in the newly proposed equation. The uncertainty of the determination of the effective discharge coefficient was quantified. Verification of the new equation was carried out by comparing the values calculated by the new equation and the values measured by other authors. The work extended the application possibilities of thin-plated weirs with a triangular notch in determination of small discharges of water and extended the knowledge of weir behaviour.
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Full-width thin-plate rectangular weir influenced by channel width
Zmítko, Jakub ; Roušar,, Ladislav (referee) ; Zachoval, Zbyněk (advisor)
The diploma thesis deals with the propagation of a weir (channel) width on the weir capacity. The influence rate is analyzed by laboratory measurements on models with a weir (channel) width of 0,02 m to a width of 0,50 m. Different heads are analyzed and different discharges that calculate the discharge coefficient. The results are compared with previous works, especially with the work of Kindsvater and Carter (1957) and of Schoder and Turner (1929), where the same procedures are used to calculate discharge coefficients. The thesis contains a theoretical introduction to the problem of thin-plate weirs and the problem of the formation of the boundary layer in the flow of liquid, following with the analytical part. In the analytical part, the results of measurements, their comparison, and evaluation are published. The work is completed with evaluation and recommendations.
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Analysis of the Exploration Range of Triangular–Notch Thin–Plate Weirs
Pospíšilík, Šimon
As first significant experiment with an overflow over triangular-notch thin-plate weirs can be considered Thomson's from 1858. Following Thomson's measurements, a number of experiments were performed, especially in the first half of the 20th century. Selected experiments were then summarized in 1981 by Shen. The article deals with the collection of available publications on the topic of overflow over triangular–notch thin–plate weirs until 2021 and analysis of the range of used geometric parameters and liquid properties, which were triangular–notch angle, upstream gauged head above crest level "overflow head", height of the crest relative to the floor, and the temperature of the used water.
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Full-width thin-plate rectangular weir influenced by channel width
Zmítko, Jakub ; Roušar,, Ladislav (referee) ; Zachoval, Zbyněk (advisor)
The diploma thesis deals with the propagation of a weir (channel) width on the weir capacity. The influence rate is analyzed by laboratory measurements on models with a weir (channel) width of 0,02 m to a width of 0,50 m. Different heads are analyzed and different discharges that calculate the discharge coefficient. The results are compared with previous works, especially with the work of Kindsvater and Carter (1957) and of Schoder and Turner (1929), where the same procedures are used to calculate discharge coefficients. The thesis contains a theoretical introduction to the problem of thin-plate weirs and the problem of the formation of the boundary layer in the flow of liquid, following with the analytical part. In the analytical part, the results of measurements, their comparison, and evaluation are published. The work is completed with evaluation and recommendations.
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The determination of countercurrent process of water surface level decrease before the thin-plate V-notch weirs
Kopečná, Monika ; Šafář,, Robert (referee) ; Žoužela, Michal (advisor)
This diploma thesis deals with finding the minimal countercurrent distance of the water surface sensors used in practice for use with a V-notch weir. The thesis complements the previously obtained results of measurements in the longitudinal vertical plane of symmetry of the inlet channel with measurements on the whole countercurrently located plane of the inlet channel. The measurements are obtained experimentally in the water management research laboratory at the Department of the Water Structures Faculty of Civil Engineering in Brno. Measurements on each individual weir with top angle cutouts of 90°, 53°8´ and 28°4´ are taken at five possible positions of the sensor towards the plane of the measuring weir. All measurements are also repeated for three different vertical distances between the lowest level of the spillway edge and the bottom of the inlet channel. The obtained data are evaluated and subsequently the minimal distances for the location of the water surface sensor in front of a counter weir is determined. The thesis also includes recommendations for practical application presented in the form of text, tables and also graphically.
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The hydraulic modelling research of specific shutter intended for determination of water flow in circular profiles with free surface
Heřmanová, Lenka ; Šafář, Robert (referee) ; Žoužela, Michal (advisor)
The main outcome of this Thesis is a set of Q / h characteristic that was obtained extensive hydraulic model research measuring plate designed for the determination of water flow in circular profiles. The final Q / h characteristic are functions of angle and vertical cut remoteness of the top slot from the bottom of the measurement aperture. Part of the output is an overview of the expected values of uncertainties of measurement in practical use in a specific aperture in sewers and evaluation of impacts involved in determining the overall uncertainty of the flow. The performed hydraulic modeling research is therefore possible to determine Q / h and characteristics for circular sections of larger diameter and to determine their uncertainties when using specific plate. For the design and shape measuring plate of the profile with larger average output is part of a supplement for quick design of specific screens.
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Assessment effects substandard tributaries flowing a proportion on Q/h characteristics thin-plate weir with a rectangular cutout
Šmidrkalová, Nina ; Šafář, Robert (referee) ; Žoužela, Michal (advisor)
This master´s thesis deals with the problem of measuring flow, especially using the method of Q/H characteristics. It describes the thin-plate weir and mentions specific channels. The master´s thesis suggests options of monitoring flow capacity in fixed proffiles with free surface. The master´s thesis also includes an experiment, which is focused on simulation of substandard tributary flowing proportions before weirs for determining their effect on Q/H characteristcs. The experiment is carried out on a thin-plate weir with a rectangular notch at the Department of Water Structures at the Faculty of Civil Engeneering in Brno. Another part of the master´s thesis is data processing to get an idea about the impact of the phenomenon in real applications. Finally, options are recommended for follow-up research.
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