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Measurements of 3D Flow Field Behind the Blade Cascade SE 1050
Šimurda, David ; Luxa, Martin
The paper is concerned with measurements of 3D flow field at exit of the Blade Cascade SE1050. Data was collected using traversing device with a small five-hole conical probe. Prior to measurements of the flow exiting the blade cascade, investigations of inlet velocity profile and inlet turbulence intensity were conducted. Measurements of exit flow field were performed at design angle of incidence and at a transonic and a subsonic regime. Data analysis reveals development of distinctive vortex structures resulting from non-uniform inlet velocity profile. Origin of these structures results in increased loss of kinetic energy and spanwise shift of kinetic energy loss coefficient distribution.
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Vortex Structures in an Excited Impinging Jet Flow
Vejražka, Jiří ; Tihon, Jaroslav ; Cvetković, D.
The behavior of vortex structures is studied in an impinging jet of Reynolds number 10 000. The effect of the modulation of the nozzle exit velocity on the flow structure is studied by means of hot-wire anemometry. It is found that the velocity field can be modified by excitations of a wide range of frequencies. In most cases the excitation yields formation of large vortices, which provoke an unsteady flow separation at their impact onto the wall. The excitation at higher frequencies suppresses the roll-up of large eddies. The velocity fluctuations near the wall are then suppressed and the flow separation disappears. The effect is documented by phase averaging for the low nozzle-to-plate spacing. The time-averaged measurements show that the unsteady flow separation can be suppressed even for nozzle-to-plate spacing up to eight diameters.
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Identifikace vírových struktur z experimentálních dat
Šonský, Jiří ; Něnička, Václav ; Jágerská, J.
For identification of vortex structures of a heat flow in a free burning plasma jet a new method is used, which utilize fast imaging methods and computerized image processing. This method allows us to observe genesis of vortexes of a heat flow in a plasma jet, including the changes when a wall barrier is inserted in the jet. These two regimes are typical for behaviour of a plasma jet in technological applications. By varying the flow rate of working gas (argon, 15slm to 150 slm) there appear considerable changes both in time and spatial distribution of vortex fields in the two above regimes
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