CLOSED-LOOP SEPARATION CONTROL USING OSCILLATORY FLOW EXCITATION... NASA PDF Download

Author: United States. National Aeronautics and Space Administration
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781726241441
Category :
Languages : en
Pages : 26

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Design and implementation of a digital feedback controller for a flow control experiment was performed. The experiment was conducted in a cryogenic pressurized wind tunnel on a generic separated configuration at a chord Reynolds number of 16 million and a Mach number of 0.25. The model simulates the upper surface of a 20% thick airfoil at zero angle-of-attack. A moderate favorable pressure gradient, up to 55% of the chord, is followed by a severe adverse pressure gradient which is relaxed towards the trailing edge. The turbulent separation bubble, behind the adverse pressure gradient, is then reduced by introducing oscillatory flow excitation just upstream of the point of flow separation. The degree of reduction in the separation region can be controlled by the amplitude of the oscillatory excitation. A feedback controller was designed to track a given trajectory for the desired degree of flow reattachment and to improve the transient behavior of the flow system. Closed-loop experiments demonstrated that the feedback controller was able to track step input commands and improve the transient behavior of the open-loop response.Allan, Brian G. and Juang, Jer-Nan and Raney, David L. and Seifert, Avi and Pack, latunia G. and Brown, Donald E.Langley Research CenterFEEDBACK CONTROL; BOUNDARY LAYER SEPARATION; BOUNDARY LAYER CONTROL; WIND TUNNEL TESTS; CONTROLLERS; SEPARATED FLOW; OSCILLATING FLOW; AIRFOILS; EXCITATION; CRYOGENIC WIND TUNNELS; ANGLE OF ATTACK; DIGITAL SYSTEMS; LOW REYNOLDS NUMBER; PRESSURE GRADIENTS; SHEAR LAYERS; TRAILING EDGES; VORTICES...

Author: Brian G. Allan
Publisher:
ISBN:
Category :
Languages : en
Pages : 30

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Author: Rudibert King
Publisher: Springer Science & Business Media
ISBN: 3540714391
Category : Technology & Engineering
Languages : en
Pages : 441

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This book contains contributions presented at the Active Flow Control 2006 conference, held September 2006, at the Technische Universität Berlin, Germany. It contains a well balanced combination of theoretical and experimental state-of-the-art results of Active Flow Control. Coverage combines new developments in actuator technology, sensing, robust and optimal open- and closed-loop control and model reduction for control.

Author: Marianna Braza
Publisher: Springer Science & Business Media
ISBN: 1402098987
Category : Science
Languages : en
Pages : 588

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This Volume is the Proceedings of the IUTAM Symposium on Unsteady Separated Flows and Their Control held in Corfu, Greece, 18–22 June 2007. This was the second IUTAM Symposium on this subject, following the symposium in Toulouse, in April 2002. The Symposium consisted of single plenary sessions with invited lectures, - lected oral presentations, discussions on special topics and posters. The complete set of papers was provided to all participants at the meeting. The thematic sessions of this Symposium are presented in the following: Experimental techniques for the unsteady ow separation Theoretical aspects and analytical approaches of ow separation Instability and transition Compressibility effects related to unsteady separation Statistical and hybrid turbulence modelling for unsteady separated ows Direct and Large-Eddy Simulation of unsteady separated ows Theoretical/industrial aspects of unsteady separated ow control This IUTAM Symposium concerned an important domain of Theoretical and Applied Mechanics nowadays. It focused on the problem of ow separation and of its control. It achieved a uni ed approach regrouping the knowledge provided from theoretical, experimental, numerical simulation and modelling aspects for unsteady separated ows (incompressible and compressible regimes) and included ef cient control devices to achieve attenuation or suppression of separation. The subject - eas covered important themes in the domain of fundamental research as well as in the domain of applications.

Author: Thomas Meurer
Publisher: Springer Science & Business Media
ISBN: 9783540279389
Category : Technology & Engineering
Languages : en
Pages : 440

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This volume presents a well balanced combination of state-of-the-art theoretical results in the field of nonlinear controller and observer design, combined with industrial applications stemming from mechatronics, electrical, (bio–) chemical engineering, and fluid dynamics. The unique combination of results of finite as well as infinite–dimensional systems makes this book a remarkable contribution addressing postgraduates, researchers, and engineers both at universities and in industry. The contributions to this book were presented at the Symposium on Nonlinear Control and Observer Design: From Theory to Applications (SYNCOD), held September 15–16, 2005, at the University of Stuttgart, Germany. The conference and this book are dedicated to the 65th birthday of Prof. Dr.–Ing. Dr.h.c. Michael Zeitz to honor his life – long research and contributions on the fields of nonlinear control and observer design.

Author: Vassilis Theofilis
Publisher: Springer
ISBN: 3319062603
Category : Technology & Engineering
Languages : en
Pages : 281

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This book contains the outcome of the international meeting on instability, control and noise generated by massive flow separation that was organized at the Monash Center, in Prato, Italy, September 4-6, 2013. The meeting served as the final review of the EU-FP7 Instability and Control of Massively Separated Flows Marie Curie travel grant and was supported by the European Office of Aerospace Research and Development. Fifty leading specialists from twelve countries reviewed the progress made since the 50s of the last century and discussed modern analysis techniques, advanced experimental flow diagnostics and recent developments in active flow control techniques from the incompressible to the hypersonic regime. Applications involving massive flow separation and associated instability and noise generation mechanisms of interest to the aeronautical, naval and automotive industries have been addressed from a theoretical, numerical or experimental point of view, making this book a unique source containing the state-of-the-art in separated flow instability and its control.

Author: Ning Qin
Publisher: Springer Nature
ISBN: 3030296881
Category : Technology & Engineering
Languages : en
Pages : 341

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This book presents the results of a European-Chinese collaborative research project, Manipulation of Reynolds Stress for Separation Control and Drag Reduction (MARS), including an analysis and discussion of the effects of a number of active flow control devices on the discrete dynamic components of the turbulent shear layers and Reynolds stress. From an application point of view, it provides a positive and necessary step to control individual structures that are larger in scale and lower in frequency compared to the richness of the temporal and spatial scales in turbulent separated flows.

Author: Hans-Joachim Heinemann
Publisher: Springer Science & Business Media
ISBN: 1402041500
Category : Technology & Engineering
Languages : en
Pages : 507

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This book collects peer-reviewed lectures of the IUTAM Symposium on the 100th anniversary of Boundary Layer research. No other reference of this calibre, on this topic, is likely to be published for the next decade. Covers classification, definition and mathematics of boundary layers; instability of boundary layers and transition; boundary layers control; turbulent boundary layers; numerical treatment and boundary layer modelling; special effects in boundary layers.

Author: Anna-Maria R. McGowan
Publisher:
ISBN:
Category : Smart materials
Languages : en
Pages : 120

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