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Mathematical description of dynamic heat exchanger
Hvožďa, Jiří ; Hnízdil, Milan (referee) ; Kůdelová, Tereza (advisor)
This bachelor's thesis deals with an analysis of a dynamic heat exchanger, with neglect to position, described by the system of ordinary differential equations. It includes necessarily theoretical basis of ordinary differential eqations and thermomechanics, a study of ordinary differential eqations' solution existence, overview of types of heat exchangers according to various aspects.
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Determination of closing valve control moments
Benda, David ; Vosynek, Petr (referee) ; Hnízdil, Milan (advisor)
This bachelor thesis deals with the calculation of the torque on the output shaft of the four-concentric butterfly valves and experimental measurement of this torque on real manufactured valves. At the beginning is carried out a brief research, the purpose describe the basic components of the butterfly valves, its production variants of the offset disc, eventually types of fittings to piping. The main part describes the partial torque occurring on the individual components. Following data from the performer measurement and at the end are compared obtained results.
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Developement of In-Line Heat Treatment Methods
Hnízdil, Milan ; Štětina, Josef (referee) ; Pospíchal, Miroslav (referee) ; Raudenský, Miroslav (advisor)
In-line heat treatment is a part of technological process uses a phase and structure changes to obtain required mechanical properties. Heat treatment of rolled products offers a reduction of steel making costs and a creation of new steel products. For example the TRIP steel is a part of modern steels which is used in the automobile industry for higher safety of passengers. The heat treatment is often described in the literature. But the authors are often focused on the method how to get the required structure and mechanical properties for different metallic materials. Nevertheless just few articles are focused on the technical observing of temperature regimes and which parameter is necessary to consider during designing the cooling section. Eight parameters were tested by the experimental way to examine their influence on the cooling intensity. They were: gravity (orientation of the cooled surface), coolant pressure, amount of coolant spraying on the surface (the flow rate), rolling velocity, nozzle configuration, kind of nozzles (full cone or flat fan nozzle), coolant temperature and the surface quality (surface roughness and scales). All these parameters have an influence the heat transfer coefficient. Based on knowledge gained in this work was created the cooling section, which comply with the required cooling temperature regimes.
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Numerical methods for missing image processing data reconstruction
Bah, Ebrima M. ; Procházková, Jana (referee) ; Hnízdil, Milan (advisor)
The Diploma thesis deals with reconstruction of Missing data of an Image. It is done by the use of appropriate Mathematical theory and numerical algorithm to reconstruct missing information. The result of this implementation is the reconstruction of missing image information. The thesis also compares different numerical methods, and see which one of them perform best in terms of efficiency and accuracy of the given problem, hence it is used for the reconstruction of missing data.
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Effect of a Tension on Pressure Drop Across the Flexible Bank of Polymeric Hollow Fibres in Crossflow
Kroulíková, Tereza ; Baláš, Marek (referee) ; Dančová,, Petra (referee) ; Hnízdil, Milan (advisor)
Pressure drop, such as the heat transfer rate, is an important parameter in heat exchanger design. Its values also determine the required pump performance for given medium. Several empirical relationships defined for calculating the pressure drop over a bank of tubes have been preserved from the last century; however, these relationships are based on measurements performed on large rigid tubes, thus, they do not include flexibility of thin fibres, and the pressure drop values calculated by the model might not reflect reality. This dissertation thesis discusses the air-side pressure drop of a bank of hollow polymer fibres, in particular, the effect of the tension in said fibers. Therefore, other possible effects of influence, such as random fiber pitches and fiber length differences, were minimized. A special device was made for tensioning the hollow fibre heat exchanger in order to measure the pressure drop. A set of measurements was performed, and the measured values were analysed and compared to two empirical models. At the end of the thesis, two model proposals for two geometries, namely for heat exchangers with a staggered design and dimensionless pitches of 2x2 and 2x3.
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Determination of closing valve control moments
Benda, David ; Vosynek, Petr (referee) ; Hnízdil, Milan (advisor)
This bachelor thesis deals with the calculation of the torque on the output shaft of the four-concentric butterfly valves and experimental measurement of this torque on real manufactured valves. At the beginning is carried out a brief research, the purpose describe the basic components of the butterfly valves, its production variants of the offset disc, eventually types of fittings to piping. The main part describes the partial torque occurring on the individual components. Following data from the performer measurement and at the end are compared obtained results.
|
|
|
Numerical methods for missing image processing data reconstruction
Bah, Ebrima M. ; Procházková, Jana (referee) ; Hnízdil, Milan (advisor)
The Diploma thesis deals with reconstruction of Missing data of an Image. It is done by the use of appropriate Mathematical theory and numerical algorithm to reconstruct missing information. The result of this implementation is the reconstruction of missing image information. The thesis also compares different numerical methods, and see which one of them perform best in terms of efficiency and accuracy of the given problem, hence it is used for the reconstruction of missing data.
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|
|
Mathematical description of dynamic heat exchanger
Hvožďa, Jiří ; Hnízdil, Milan (referee) ; Kůdelová, Tereza (advisor)
This bachelor's thesis deals with an analysis of a dynamic heat exchanger, with neglect to position, described by the system of ordinary differential equations. It includes necessarily theoretical basis of ordinary differential eqations and thermomechanics, a study of ordinary differential eqations' solution existence, overview of types of heat exchangers according to various aspects.
|
|
|
Developement of In-Line Heat Treatment Methods
Hnízdil, Milan ; Štětina, Josef (referee) ; Pospíchal, Miroslav (referee) ; Raudenský, Miroslav (advisor)
In-line heat treatment is a part of technological process uses a phase and structure changes to obtain required mechanical properties. Heat treatment of rolled products offers a reduction of steel making costs and a creation of new steel products. For example the TRIP steel is a part of modern steels which is used in the automobile industry for higher safety of passengers. The heat treatment is often described in the literature. But the authors are often focused on the method how to get the required structure and mechanical properties for different metallic materials. Nevertheless just few articles are focused on the technical observing of temperature regimes and which parameter is necessary to consider during designing the cooling section. Eight parameters were tested by the experimental way to examine their influence on the cooling intensity. They were: gravity (orientation of the cooled surface), coolant pressure, amount of coolant spraying on the surface (the flow rate), rolling velocity, nozzle configuration, kind of nozzles (full cone or flat fan nozzle), coolant temperature and the surface quality (surface roughness and scales). All these parameters have an influence the heat transfer coefficient. Based on knowledge gained in this work was created the cooling section, which comply with the required cooling temperature regimes.
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