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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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CI-engine Variable Intake System
Cihlář, Lukáš ; Štěpánek, Karel (referee) ; Dundálek, Radim (advisor)
The master´s thesis focuses on design of intake manifold with swirl flap for diesel engine. In addition to the design of sub-components of the intake manifold are also investigated the influence of new solutions on engine parameters. The influence of the new solution is compared to the original version and a reference model simulating intake manifold used by competitors. After simulation of thermodynamics and fluid flow are evaluated each variants.
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Multiphase CFD simulation of spiral vortex in vaneless swirl generator
Zatloukal, Filip ; Burda, Radim (referee) ; Štefan, David (advisor)
This thesis deals with multiphase CFD simulation of spiral vortex in bladeless swirl generator. Spiral vortex formed in the draft tube of hydraulic turbine is called “vortex rope”. Vortex rope is formed when the turbine is forced to operate in off-design conditions. Assessment of swirl generators used for the study of vortex ropes is presented. The multiphase CFD simulations are carried out for the bladeless swirl generator with use of Reynolds stress turbulence model in ANSYS Fluent software. The results from calculations are compared with available experimental data previously measured on this particular swirl generator. The main focus is on detailed analysis of velocity field in the diffusor part of the generator where the vortex appears. Experimentally estimated swirl number is compared with the one evaluated from simulation. The swirl number is also monitored along the length of diffuser and downstream. Finally, the synchronous and asynchronous pressure pulsations are studies by means of Fast Fourier Transformation.
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Multiphase CFD simulation of spiral vortex in vaneless swirl generator
Zatloukal, Filip ; Burda, Radim (referee) ; Štefan, David (advisor)
This thesis deals with multiphase CFD simulation of spiral vortex in bladeless swirl generator. Spiral vortex formed in the draft tube of hydraulic turbine is called “vortex rope”. Vortex rope is formed when the turbine is forced to operate in off-design conditions. Assessment of swirl generators used for the study of vortex ropes is presented. The multiphase CFD simulations are carried out for the bladeless swirl generator with use of Reynolds stress turbulence model in ANSYS Fluent software. The results from calculations are compared with available experimental data previously measured on this particular swirl generator. The main focus is on detailed analysis of velocity field in the diffusor part of the generator where the vortex appears. Experimentally estimated swirl number is compared with the one evaluated from simulation. The swirl number is also monitored along the length of diffuser and downstream. Finally, the synchronous and asynchronous pressure pulsations are studies by means of Fast Fourier Transformation.
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CI-engine Variable Intake System
Cihlář, Lukáš ; Štěpánek, Karel (referee) ; Dundálek, Radim (advisor)
The master´s thesis focuses on design of intake manifold with swirl flap for diesel engine. In addition to the design of sub-components of the intake manifold are also investigated the influence of new solutions on engine parameters. The influence of the new solution is compared to the original version and a reference model simulating intake manifold used by competitors. After simulation of thermodynamics and fluid flow are evaluated each variants.
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|
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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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