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Visualisation of Boundary Layer Separation and Passive Flow Control on Airfoils and Bodies in Wind-Tunnel and In-Flight Experiments
Popelka, Lukáš ; Kuklová, J. ; Šimurda, David ; Součková, Natálie ; Matějka, Milan ; Uruba, Václav
Infrared camera, Particle Image Velocimetry, smoke-wire, tuft filaments and oil-flow visualization techniques were used for wind-tunnel and in-flight investigation of boundary layer separation, both stall and separation bubbles, related to the low-Reynolds numbers transition mechanism. Airfoils of Wortmann FX66 series and FX66 series wing-fuselage interaction, as well as modern airfoils and their wing-fuselage geometry were subject to study. The presence of previously identified structures in the CFD modelling, such as horse-shoe vortices, was confirmed in the flow.
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The rise and development constructions
MATĚJKA, Milan
This baccalaureate work is occupied problems of architecture styles. It is devided into two parts. Theoretical part is based on the hystory of constructions from long past cultures. Individual architecture styles are arranged in chronological sequence running from past to the present. Change from the first part to second part is made of chapter about the construction of underground in Prague and its compare with tunnel Blanka. Practical part is based on the real realization of tunnel Blanka. There are described individual steps of construction this tunnel. More, there is attached project documentation and visual photographs. The development of tunnels stands on the top of interesting of traffic engineering and it depends on the time, when the similar constructions will be realized in the regional towns.
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Visualization of Flow Separation and Control by Vortex Generators on an Single Flap in Landing Configuration
Součková, Natálie ; Kuklová, J. ; Popelka, Lukáš ; Matějka, Milan
This paper focuses on a suppression of the flow separation, which occurs on a deflected flap, by means of vortex generators (VG's). An airfoil NACA 63A421 with a simple flap and vane-type vortex generators were used. The investigation was carried out by using experimental and numerical methods. The data from the numerical simulation of the flapped airfoil without VG's control were used for the vortex generator design. Two sizes, two different shapes and various spacing of the vortex generators were tested. The flow past the airfoil was visualized through three methods, namely tuft filaments technique, oil and thermo camera visualization. The experiments were performed in closed circuit wind tunnels with closed and open test sections. The lift curves for both cases without and with vortex generators were acquired for a lift coefficient improvement determination. The improvement was achieved for several cases by means all of the applied methods.
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Numerická simulace aerodynamické interakce křídla a trupu
Šimurda, David ; Popelka, Lukáš ; Zelený, L. ; Matějka, Milan
In order to investigate and understand extent of the wing-body interaction effects taking place during operation of a particular self-launching sailplane, commercial code Fluent 6.3 was used for numerical simulation of flow past a simplified model of TST-10a. Several methods were used to identify vortex structures originating due to interference effects in this part of the aircraft. 3D effects and distortions of pressure and velocity distributions taking place in the junction of the body and the fuselage were observed.
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Dynamika odtržení řízené mezní vrstvy na válci
Uruba, Václav ; Matějka, Milan ; Procházka, Pavel
Dynamical aspects of the boundary layer separation on a circular cylinder in cross-flow are studied experimentally. Two cases are compared, the base case and the case with excitation using a synthetic jet actuator. The TR-PIV technique was used to catch both space and time velocity field correlations. Instantaneous velocity fields and skin friction distributions are evaluated. For dynamical structures study, the BOD method was applied based on energetic principle. Dynamical modes connected with vortex shedding process, dynamical excitation by synthetic jet and transition to turbulence are identified.
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Pasivní a aktivní metody řízení mezní vrstvy
Matějka, Milan ; Popelka, Lukáš
The paper deals with influence of the passive and active method of control on the flow field. It is well known fact that boundary layer separation has a fundamental effect on aircraft airfoil performance, compressors and turbines performance and other bodies, subject to study of internal and external aerodynamics. By the boundary layer control, it is possible to obtain both operational economy and extension of efficient operational region. Traditional methods of active boundary layer control are very complex and their application needs complex facilities. Modern methods based on the control by synthetic jets or plasma actuator are simpler, but their design has to be carried out at rather well experience and detailed knowledge about boundary layer and its interaction with the actuator.
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