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Application of an anemometric hot-wire probe to the measurement of a velocity field downstream of an automotive ventilation outlet
Šíp, Jan ; Tuhovčák, Ján (referee) ; Lízal, František (advisor)
This diploma thesis deals with the research of the flow in front of the benchmark automotive vent. Using thermoanemometry, the velocity field in the area in front of the vent was measured in detail and the intensity of the turbulence was calculated. Computational fluid dynamics of the air flow from the vent was also performed using the STAR-CCM + program. In addition, the influence of the surrounding surfaces simulating the real environment of the automobile on the air flow from the vent was investigated. The diploma thesis contains the calculation of measurement uncertainty. The purpose of this thesis is to obtain complex data on the velocity field and to use them for validation of Computational fluid dynamics.
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Lateral recirculation zones of flow in approach channel of weir
Korálová, Nikola ; Pařílková, Jana (referee) ; Zachoval, Zbyněk (advisor)
The bachelor’s thesis is divided in to the literary research and practical part. The content of the literary research is the issue of side contracted weirs, where occurs side contracted flow. The sudden change of the channel width and formation of upstream wake have direct influence on value of discharge coefficient. There are described types of the weirs, ways of computing discharge and discharge coefficients which are influenced by contraction. In the practical part of thesis is described measurement of the velocity field of side contracted flow by UVP Monitor, follow up by assessment of boundary of the upstream wake, which is situated in the approach channel in front of the weir.
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Oblique collisions of non-rotating spherical particles with a wall
Chára, Zdeněk ; Vlasák, Pavel ; Kysela, Bohuš
In the present paper non-rotating particle-wall collisions were experimentally investigated. By means of the PIV method a velocity field around falling spheres was analyzed. It was shown that the wake behind the particle which approached a bed in non-normal direction was asymmetrical and after the impact the wake passed the particle only along one side. This non-symmetrical velocity field resulted in additional forces which pushed the particle to an opposite direction than was the direction of the particle motion just after the impact.
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Study of velocity field in crossroads areas
Kellnerová, Radka ; Jaňour, Zbyněk
The aim of this project is to study the influence of boundary conditions on contaminant spreading in a urban area model. The urban area model was composed of simple elements shapes of crossroads: X-shaped, T-shaped and skew intersection. The project at the beginning - by now only results for T-shaped crossroads are available. The experiment took place in an environmental aerodynamics tunnel IT AS CR in Nový Knín. First results show accumulation of high values of Reynolds stress above the area of crossroads center, whereas the velocity field is weaker when compared with more remote area. In specific distance from the intersection the recirculating zone appears. With increasing distance from intersection the center of zone moves counter main flow and up.
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Measurement of the velocity field in a ribbed channel
Chára, Zdeněk
The contribution deals with an experimental investigation of the turbulent along a ribbed channel bottom. The main goal is an application of ultrasound velocity profile technique for measurement of the turbulent flow characteristics in complex geometries. Four configurations of the ribbed surfaces were tested with fixed ribs of square cross section and variable groove widths. The experiments were performed in a water channel.
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Short-time turbulent disturbances in pulsatile flow
Kořenář, Josef
In the pulsatile flow in tubes near the laminar/turbulent transition zone, the short-time turbulent disturbances arise and fade away in every period. Moment of arise, endurance, course of intensity and moment of disappearing of those disturbances within a period are dependent on flow parameters like mean Reynolds number, Womersley number and flow rate ratio.
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