The MEGAFLOW project

Kroll, Norbert; Rossow, Cord-Christian; Becker, Klaus; Thiele, Frank

doi:10.1016/s1270-9638(00)00131-0

Cited by 185 publications

(43 citation statements)

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“…This simulation technique is used within the flow solver FLOWer which was originally developed by the German Aerospace Center (DLR) [7] and is constantly extended at the Institute of Aerodynamics and Gas Dynamics (IAG). The implementation of the actuator line method is performed according to [8], [9].…”

Section: Methodsmentioning

confidence: 99%

Actuator Line Method Simulations for the Analysis of Wind Turbine Wakes Acting on Helicopters

Bühler

Weihing

Klein

et al. 2018

J. Phys.: Conf. Ser.

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Abstract. In the present study the actuator line method is used to simulate the wake of a wind turbine and ways to characterize its impact on the flight of a helicopter model through the wake are evaluated. The helicopter within the simulation setup is represented by a dynamic actuator line which was implemented into the flow solver FLOWer. In order to evaluate the loads on the helicopter the thrust force distribution is compared in different areas of the wake. For further improvement of the actuator line implementation different methods to evaluate the angle of attack are compared. This was examined as the angle of attack is a highly important parameter for the actuator line and helps to optimise the accuracy and performance of the actuator line method. As there is no experimental data available and the model of the helicopter comes with distinct simplifications the loads are compared to values without the wake of the wind turbine, thus in free flight.

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Section: Methodsmentioning

confidence: 99%

Actuator Line Method Simulations for the Analysis of Wind Turbine Wakes Acting on Helicopters

Bühler

Weihing

Klein

et al. 2018

J. Phys.: Conf. Ser.

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“…The computational studies employ the computational fluid dynamics (CFD) code FLOWer from the German Aerospace Center [10]. The spatial discretization scheme uses a central cell-centered Jameson-Schmidt-Turkel finite volume formulation because it provides high robustness and is well-suited for parallel applications.…”

Section: Computational Setupmentioning

confidence: 99%

Active separation control on a very thick wind turbine airfoil - A URANS and DDES perspective

Bangga

Lutz

Krämer

2018

J. Phys.: Conf. Ser.

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Abstract. The present works aim to investigate the effectiveness of active separation control by means of combined suction and vortex generator jets on the suction side of a very thick airfoil (40%) under tripped conditions. Fully resolved two-dimensional URANS and three-dimensional DDES simulations were carried out to assess the consistency of the results. It is observed for the baseline case that 2D URANS simulations are too optimistic while 3D DDES delivers an excellent agreement with the available experiment in the post stall region at α = 20• . The studies reveal that the proposed system is able to delay separation significantly, increasing the overall aerodynamic performance of the airfoil.

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“…For the present study, the block-structured finite-volume solver of the compressible Navier-Stokes equations FLOWer (Kroll et al, 2000) by DLR has been used. This code is well suited for simulation of rotary wings, since the fluxes caused by relative grid movements are taken into account.…”

Section: Flow Solver and Numerical Settingsmentioning

confidence: 99%

Numerical analyses and optimizations on the flow in the nacelle region of a wind turbine

et al. 2018

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Abstract. The present study investigates flow dynamics in the hub region of a wind turbine focusing on the influence of nacelle geometry on the root aerodynamics by means of Reynolds averaged Navier-Stokes simulations with the code FLOWer. The turbine considered is a generic version of the Enercon E44 converter incorporating blades with flat-back-profiled root sections. First, a comparison is drawn between an isolated rotor assumption and a setup including the baseline nacelle geometry in order to elaborate the basic flow features of the blade root. It was found that the nacelle reduces the trailed circulation of the root vortices and improves aerodynamic efficiency for the inner portion of the rotor; on the other hand, it induces a complex vortex system at the juncture to the blade that causes flow separation. The origin of these effects is analyzed in detail. In a second step, the effects of basic geometric parameters describing the nacelle have been analyzed with the purpose of increasing the aerodynamic efficiency in the root region. Therefore, three modification categories have been addressed: the first alters the nacelle diameter, the second varies the blade position relative to the nacelle and the third comprises modifications in the vicinity of the blade-nacelle junction. The impact of the geometrical modifications on the local flow physics are discussed and assessed with respect to aerodynamic performance in the blade root region. It was found that increasing the nacelle diameter deteriorates the root aerodynamics, since the flow separation becomes more pronounced. Possible solutions identified to reduce the flow separation are a shift of the blade in the direction of the rotation or the installation of a fairing fillet in the junction between the blade and the nacelle.

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The MEGAFLOW project

Cited by 185 publications

References 0 publications

Actuator Line Method Simulations for the Analysis of Wind Turbine Wakes Acting on Helicopters

Actuator Line Method Simulations for the Analysis of Wind Turbine Wakes Acting on Helicopters

Active separation control on a very thick wind turbine airfoil - A URANS and DDES perspective

Numerical analyses and optimizations on the flow in the nacelle region of a wind turbine

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