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Parallel numerical simulation of airflow past an oscillating NACA0015 airfoil
Řidký, Václav ; Šidlof, Petr ; Vlček, Václav
This paper focuses on 3D and 2D parallel computation of pressure and velocity fields around an elastically supported airfoil self-oscillating due to interaction with the airflow The results of numerical simulations are compared with data measured in a wind tunnel, where physical model of a NACA0015 airfoil was mounted and tuned to exhibit the flutter instability. The experimental results were obtained previously in the Institute of Thermomechanics by interferometric measurements in a subsonic wind tunnel in Nový Knín. For the numerical solution is implemented in OpenFOAM, an open-source software package based on finite volume method. In the numerical solution is prescribed displacement of the airfoil, which corresponds to the experiment.
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Numerical simulations of the flow with the prescribed displacement of the airfoil and comparison with experiment
Řidký, Václav ; Šidlof, Petr ; Vlček, Václav
The work is devoted to comparing measured data with the results of numerical simulations. As mathematical model was used mathematical model whitout turbulence for incompressible flow In the experiment was observed the behavior of designed NACA0015 airfoil in airflow. For the numerical solution was used OpenFOAM computational package, this is open-source software based on finite volume method. In the numerical solution is prescribed displacement of the airfoil, which corresponds to the experiment. The velocity at a point close to the airfoil surface is compared with the experimental data obtained from interferographic measurements of the velocity field. Numerical solution is computed on a 3D mesh composed of about 1 million ortogonal hexahedron elements. The time step is limited by the Courant number. Parallel computations are run on supercomputers of the CIV at Technical University in Prague and on a computer cluster of the Faculty of Mechatronics of Liberec . Run time is fixed at five periods, the results from the fifth periods and average value for all periods are then be compared with experiment.
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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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Řízení mezní vrstvy na profilu s vychýlenou klapkou pomocí vírových generátorů
Součková, Natálie ; Šimurda, David ; Popelka, Lukáš
The paper focuses on reducing eventually removing flow separation, which is occurred on deflected flap, with vortex generators. Airfoil NACA 63A421 with simple flap and low profile vane-type vortex generators were used. The investigation was carried out using experimental and numerical method. The flow over the airfoil was visualized by tuft filaments technique in closed circuit wind tunnel for two flap deflections and four angles of attack. Two size and two different shapes of vortex generators were tested. The data from numerical simulation of flapped airfoil without VG's control were used for vortex generator designing.
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Řízení mezní vrstvy na profilu s vychýlenou klapkou pomocí vírových generátorů
Součková, Natálie ; Šimurda, David ; Popelka, Lukáš
The paper focuses on reducing eventually removing flow separation, which is occurred on deflected flap, with vortex generators. Airfoil NACA 63A421 with simple flap and low profile vane-type vortex generators were used. The investigation was carried out using experimental and numerical method. The flow over the airfoil was visualized by tuft filaments technique in closed circuit wind tunnel for two flap deflections and four angles of attack. Two size and two different shapes of vortex generators were tested. The data from numerical simulation of flapped airfoil without VG's control were used for vortex generator designing.
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Aerodynamická optimalizace profilů pro větroně
Popelka, Lukáš ; Matějka, M.
The article describes procedure of sailplane airfoil optimization with use of available numerical and experimental methods. Comments are given on calculation of boundary layer transition, integral parameters, measurement of maximum lift coefficient, visualization and flow control.
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