Suppression of Wind Tunnel Buffeting by Active Flow Control

Author(s):  
Wilhelm von Heesen ◽  
Matthias Höpfer
Author(s):  
Glenn Saunders ◽  
Edward Whalen ◽  
Helen Mooney ◽  
Sarah Zaremski

The design, fabrication and installation of an approximately 1/6 scale model of an aircraft vertical stabilizer for research in Active Flow Control (AFC) is discussed. Highlighted are the unique design requirements of wind tunnel models, the specialized fabrication techniques employed to create them and the required close collaboration between industry, government and three academic institutions. The design of the model involves often competing constraints imposed by structural, instrumentation, aerodynamic, manufacturability and research-agenda considerations as well as cost and schedule. Instrumentation requires hundreds of pressure ports and six-axis force/torque sensing. Aerodynamic considerations necessitate high manufacturing precision, highly-skilled fabrication techniques and careful observance of model geometry throughout the design and fabrication processes. A scale model of a vertical stabilizer for AFC research was successfully designed, fabricated and deployed. The collaboratively designed model satisfies the structural, aerodynamic and research design constraints, and furthers the state of the art in Active Flow Control research.


2017 ◽  
Vol 89 (5) ◽  
pp. 709-718 ◽  
Author(s):  
Philipp Schloesser ◽  
Michael Meyer ◽  
Martin Schueller ◽  
Perez Weigel ◽  
Matthias Bauer

Purpose The area behind the engine/wing junction of conventional civil aircraft configurations with underwing-mounted turbofans is susceptible to local flow separation at high angles of attack, which potentially impacts maximum lift performance of the aircraft. This paper aims to present the design, testing and optimization of two distinct systems of fluidic actuation dedicated to reduce separation at the engine/wing junction. Design/methodology/approach Active flow control applied at the unprotected leading edge inboard of the engine pylon has shown considerable potential to alleviate or even eliminate local flow separation, and consequently regain maximum lift performance. Two actuator systems, pulsed jet actuators with and without net mass flux, are tested and optimized with respect to an upcoming large-scale wind tunnel test to assess the effect of active flow control on the flow behavior. The requirements and parameters of the flow control hardware are set by numerical simulations of project partners. Findings The results of ground test show that full modulation of the jets of the non-zero mass flux actuator is achieved. In addition, it could be shown that the required parameters can be satisfied at design mass flow, and that pressure levels are within bounds. Furthermore, a new generation of zero-net mass flux actuators with improved performance is presented and described. This flow control system includes the actuator devices, their integration, as well as the drive and control electronics system that is used to drive groups of actuators. Originality/value The originality is given by the application of the two flow control systems in a scheduled large-scale wind tunnel test.


Author(s):  
John C. Lin ◽  
LaTunia G. Pack Melton ◽  
Judith Hannon ◽  
Marlyn Y. Andino ◽  
Mehti Koklu ◽  
...  

Author(s):  
Vlad Ciobaca ◽  
Jochen Wild ◽  
Matthias Bauer ◽  
Thomas Grund ◽  
Claus-Philipp Huehne ◽  
...  

Author(s):  
John C. Lin ◽  
LaTunia G. Pack Melton ◽  
Judith Hannon ◽  
Marlyn Andino ◽  
Mehti Koklu ◽  
...  

2013 ◽  
Author(s):  
James Dianics ◽  
Michael Balthazar ◽  
Andreas Gross ◽  
Hermann F. Fasel

2018 ◽  
Vol 28 (5) ◽  
pp. 1169-1186 ◽  
Author(s):  
Yoann Eulalie ◽  
Elisabeth Fournier ◽  
Philippe Gilotte ◽  
David Holst ◽  
Shaun Johnson ◽  
...  

Purpose This paper aims to present an experimental investigation of an active flow control solution mounted at rear of a sport utility vehicle (SUV) with the objective of drag reduction, thanks to a selection of flow control parameters leading to a pressure increase on the tailgate. Design/methodology/approach A flow control design of experiments was conducted with a pulsed jet system mounted on the top and sides of the rear window of the vehicle. The wall pressure, instantaneous velocity and drag were measured with this prototype in a wind tunnel. A dynamic modal decomposition (DMD) analysis of the pressure enables to describe the pressure fluctuations. Fluid dynamic computations show relation between pressure and velocity fields. Findings Measurements with this prototype in the wind tunnel revealed small improvements in drag for the best flow control configurations. This small benefit is because of the core of the upper span wise vortex further away from the rear window than the lower span wise vortex. These small improvements in drag were confirmed with pressure measurements on the rear window and tailgate. The DMD analysis of the surface pressure showed a low frequency pendulum oscillation on the lower area of the tailgate, linked with low velocity frequencies in the shear layers near the tailgate. Originality/value Experimental and numerical results show interest to increase pressure at bottom of the rear end of this SUV prototype. The dynamic description of the wall pressure shows importance of flow control solutions reducing pressure fluctuations at low frequencies in the lower area of the tailgate.


Author(s):  
G. Pechlivanoglou ◽  
C. N. Nayeri ◽  
C. O. Paschereit

This paper presents a series of investigations performed at the Hermann Fo¨ttinger Institute of TU Berlin. The initial scope of the investigations was the identification of Active Flow Control (AFC) solutions with significant implementation potential on wind turbine rotors. Several Active Flow Control solutions were thoroughly investigated based on extensive literature research. The performance of all the investigated solutions was ranked according to objective performance criteria and then the best performing solutions were selected for further numerical and experimental investigation. The selected Active Flow Control solutions were experimentally investigated with steady state wind tunnel measurements as well as steady state CFD simulations. The results of these investigations and the potential of each AFC solution are presented and discussed. The steady state tests were followed by a dynamic wind tunnel test campaign where the performance of one AFC solution (active Gurney flap) on a pitching test wing was investigated. The results of the static and dynamic investigations were very positive and proved the large load reduction potential of AFC on wind turbines.


2013 ◽  
Vol 50 (5) ◽  
pp. 1605-1614 ◽  
Author(s):  
Rudibert King ◽  
Notger Heinz ◽  
Matthias Bauer ◽  
Thomas Grund ◽  
Wolfgang Nitsche

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