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Characteristic parameters of fuel nozzles
Ledererová, Lucie ; Zejda, Vojtěch (referee) ; Bělohradský, Petr (advisor)
Many industrial applications acquire necessary thermal energy through the combustion process. The basic element of each combustion appliance is a burner and one~part~of~it~is a~nozzle system that supplies fuel to a combustion chamber. The geometry of the fuel nozzle significantly affects the intensity of mixing the fuel with the combustion air and thus the stability of the combustion. The main subject of~this diploma thesis is~determination of~velocity coefficients for nozzles with different geometries. The knowledge of~correct values of~velocity coefficients is a key parameter for the design of~the burner and~its subsequent operation. For the calculation of~velocity coefficients, the exit nozzle velocities were used. For chosen nozzles, a~theoretical exit nozzle velocities were calculated. They were compared with the actual exit nozzle velocities, which were measured experimentally using the hot-wire anemometry, and with velocities, which were calculated using the CFD simulation method.
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Velocity profile measurement downstream of swirler
Zejda, Vojtěch ; Hájek, Jiří (referee) ; Vondál, Jiří (advisor)
A burner is very important device in process furnaces that significantly affect the production of emissions during the combustion process. One of the key things in development of the modern low-NOX burners is the evaluation of flow field downstream of an axial blade swirler inside the burner. The computational fluid dynamics (CFD) is often used to predict the attributes of the flow. Predicted values should be validated with measurement. It is the reason why the velocity fields for several choosen swirlers were measured. The hot wire anemometry was choosen and the dual-sensor probe was used during the measurement. The data can be then used for CFD validation. This thesis describes procedure of measurement set-up. The experimental facility was designed according to the anemometry method. The new probe traversing system was designed, which provides desired accuracy. Five different swirlers were measured. Large data set, need for customized post-processing and control over calculation procedures lead to new software design. For each swirler the velocity profiles were gathered and the swirl numbers calculated. That final data were transferred in to graphical format. Uncertainty of measured data was calculated. Results show counter-rotating flow in some areas closed to the swirler. Some drawbacks of current measurement set-up are discussed. Based on the thesis reader can obtain the information and knowledge for consequent measurements of swirl burners velocity profiles.
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Analysis of flow from the car vent using thermoanemometric probe
Šeda, Libor ; Fojtlín, Miloš (referee) ; Lízal, František (advisor)
In this master’s thesis there are summarized fundamental findings about air flow velocity measurements and afterwards introduced the measuring track for automobile car vents, measured object and track arrangement and all used components. Velocity field measurement method is how wire anemometry, and apart from 4 main cases measurements of free air jet, there are velocity profiles in piping measured as an input for CFD simulation. Air vent evaluation criteria are described and their assessment is done for specified cases. Further, there is a CFD simulation presented with comparison to experimental data. Uncertainty of flow rate measured and flow rate setting is determined. Improvement points and encountered issues are presented. Visualization and evaluation program coded in MATLAB environment enables easy data display of CTA results and will serve further vent quality assessment.
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Characteristic parameters of fuel nozzles
Ledererová, Lucie ; Zejda, Vojtěch (referee) ; Bělohradský, Petr (advisor)
Many industrial applications acquire necessary thermal energy through the combustion process. The basic element of each combustion appliance is a burner and one~part~of~it~is a~nozzle system that supplies fuel to a combustion chamber. The geometry of the fuel nozzle significantly affects the intensity of mixing the fuel with the combustion air and thus the stability of the combustion. The main subject of~this diploma thesis is~determination of~velocity coefficients for nozzles with different geometries. The knowledge of~correct values of~velocity coefficients is a key parameter for the design of~the burner and~its subsequent operation. For the calculation of~velocity coefficients, the exit nozzle velocities were used. For chosen nozzles, a~theoretical exit nozzle velocities were calculated. They were compared with the actual exit nozzle velocities, which were measured experimentally using the hot-wire anemometry, and with velocities, which were calculated using the CFD simulation method.
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|
|
Velocity profile measurement downstream of swirler
Zejda, Vojtěch ; Hájek, Jiří (referee) ; Vondál, Jiří (advisor)
A burner is very important device in process furnaces that significantly affect the production of emissions during the combustion process. One of the key things in development of the modern low-NOX burners is the evaluation of flow field downstream of an axial blade swirler inside the burner. The computational fluid dynamics (CFD) is often used to predict the attributes of the flow. Predicted values should be validated with measurement. It is the reason why the velocity fields for several choosen swirlers were measured. The hot wire anemometry was choosen and the dual-sensor probe was used during the measurement. The data can be then used for CFD validation. This thesis describes procedure of measurement set-up. The experimental facility was designed according to the anemometry method. The new probe traversing system was designed, which provides desired accuracy. Five different swirlers were measured. Large data set, need for customized post-processing and control over calculation procedures lead to new software design. For each swirler the velocity profiles were gathered and the swirl numbers calculated. That final data were transferred in to graphical format. Uncertainty of measured data was calculated. Results show counter-rotating flow in some areas closed to the swirler. Some drawbacks of current measurement set-up are discussed. Based on the thesis reader can obtain the information and knowledge for consequent measurements of swirl burners velocity profiles.
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Analysis of flow from the car vent using thermoanemometric probe
Šeda, Libor ; Fojtlín, Miloš (referee) ; Lízal, František (advisor)
In this master’s thesis there are summarized fundamental findings about air flow velocity measurements and afterwards introduced the measuring track for automobile car vents, measured object and track arrangement and all used components. Velocity field measurement method is how wire anemometry, and apart from 4 main cases measurements of free air jet, there are velocity profiles in piping measured as an input for CFD simulation. Air vent evaluation criteria are described and their assessment is done for specified cases. Further, there is a CFD simulation presented with comparison to experimental data. Uncertainty of flow rate measured and flow rate setting is determined. Improvement points and encountered issues are presented. Visualization and evaluation program coded in MATLAB environment enables easy data display of CTA results and will serve further vent quality assessment.
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