Author: L. MongeauPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Active Control of Flow-induced Cavity Resonance
Author: L. MongeauReview of Active Control of Flow-induced Cavity Resonance
Author: Louis CattafestaActive Flow Control
Author: Rudibert KingPublisher: Springer Science & Business Media
ISBN: 3540714391
Category : Technology & Engineering
Languages : en
Pages : 441
Book Description
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.
Experimental Investigation of Flow-induced Cavity Resonance
Author: Paul Zoccola (Jr., J.)Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 200
Book Description
Active Control of Flow-induced Acoustic Resonance Through Surface Perturbation
Author: Zhenbo LuPublisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 424
Book Description
4) Closed-loop tests were proposed for a semi-circular leading edge test model, along with a down-sampling control algorithm. It was observed that the closed-loop control could achieve a better control performance than that of the open-loop control. At the optimum control voltage and control phase delay, a noise reduction of 17.5 dB in the duct and 22.6 dB inside the cavity was obtained. In particular, the phase delay of control actuation could be optimally tuned so that the strength of vortex shedding energy could be minimized effectively, leading to a satisfactory noise reduction in the duct and cavity. This process was evident from the spectral phase shift results, where the vortex traveling time has been delayed at downstream of the test model. 5) For the square leading edge test model, the developed surface perturbation technique was also effective. However, the control mechanism was found to be different from that of the semi-circular leading edge test model. The path of the leading edge vortex shedding started from the leading edge and then propagated downstream. The vertical velocity generated by the perturbation played the key role in the vortex strength reduction. More significant reductions can be achieved when the velocity disturbance was near the propagation path of the vortex shedding. 6) The control strategies for two primary leading edge geometries have been investigated. The optimal control strategy for the semi-circular leading edge test model consists in arranging the perturbation at the position where the pressure pulse was the smallest. This way, the targeted noise reduction can be achieved by using perturbation within a relatively small area at a low control voltage. While for the square leading edge test model, the optimal control strategy requires applying the perturbation near the propagation path of the LEVS for achieving sufficient vortex strength abasement. 7) The energy distribution at vortex shedding frequency along the up surface of test model measured by the hot wire was used to identify the existence of the pressure pulse for the semi-circular leading edge test model. It was found that the pressure pulse had strong directivity characteristics; therefore, a small disturbance generated by the surface perturbation can change the direction of the pressure pulse and then influence the generation the vortex shedding.
Flow-Induced Vibration
Author: S. ZiadaPublisher: CRC Press
ISBN: 1482283743
Category : Science
Languages : en
Pages : 863
Book Description
Flow-induced vibrations and noise continue to cause problems in a wide range of engineering applications ranging from civil engineering and marine structures to power generation and chemical processing. These proceedings bring together more than a hundred papers dealing with a variety of topics relating to flow-induced vibration and noise. The cont
Flow Control
Author: Thomas C. CorkePublisher: Cambridge University Press
ISBN: 110896253X
Category : Technology & Engineering
Languages : en
Pages : 482
Book Description
This book provides a comprehensive treatment of passive and active flow control in fluid dynamics, with an emphasis on utilizing fluid instabilities for enhancing control performance. Examples are given from a wide range of technologically important flow fields occurring in aerospace applications, from low-subsonic to hypersonic Mach numbers. This essential book can be used for both research and teaching on the topics of fluid instabilities, fluid measurement and flow actuator techniques, and problem sets are provided at the end of each chapter to reinforce key concepts and further extend readers' understanding of the field. The solutions manual is available as a online resource for instructors. The text is well suited for both graduate students in fluid dynamics and for practising engineers in the aerodynamics design field.
Bill Henderson
Author: Flow Control Techniques and Applications
Author: Jinjun WangPublisher: Cambridge University Press
ISBN: 1107161568
Category : Science
Languages : en
Pages : 293
Book Description
Master the theory, applications and control mechanisms of flow control techniques.
Model-based Feedback Control of Cavity Resonance
Author: Clarence W. RowleyPublisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 60
Book Description
This report presents results of experiments and numerical simulations studying closed-loop feedback control of oscillations in the compressible flow past a rectangular cavity. When weapons bays are exposed to high flow speeds, extremely large pressure fluctuations result, and are often large enough to cause structural damage to the aircraft and internal stores. The goal of this work is to design an implement a model-based feedback controller to suppress oscillations in the flow past a cavity over a range of operating conditions, using much less power than open-loop techniques; and to understand the physics well enough to allow the techniques to be reliably transferred to full-scale aircraft. Several specific advances have been made in this work, relevant for cavity flow control as well as for other closed-loop flow control applications. Theoretical models are presented for temporally developing shear layers and cavity oscillations at the flow conditions used in both simulations and experiments. These models can be used to construct dynamic observers, which reconstruct the full flow information from a limited number of sensors, and significantly outperform static estimators such as Linear Stochastic Estimation (LSE).