Results 261 to 270 of about 811,380 (302)

Passive Control of Transonic Cavity Flow

Journal of Fluids Engineering, 2008
Abstract Open cavities at transonic speeds can result in acoustic resonant flow behavior with fluctuating pressure levels of sufficient intensity to cause significant damage to internal stores and surrounding structures. Extensive research in this field has produced numerous cavity flow control techniques, the more effective of which may
David G. MacManus, Diane S. Doran
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Flow Seperation and Passive Flow Control on E387 Airfoil

54th AIAA Aerospace Sciences Meeting, 2016
The behavior of a MVG vane at three different design angles was simulated with LES on an Eppler e387 airfoil that was suffering flow separation. The e387 airfoil was placed at an angle of attack of 12 degrees and at Reynolds number of 200,000 based on the chord length. Different parameters of the generated vortex from the MVG were analyzed to study the
Andrew Heffron, John J. Williams, Eldad J. Avital   +2 more
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Passive feedback control of transonic buffet flow

Physics of Fluids, 2019
The activated structural degree of freedom often causes undesirable large-amplitude structural vibrations in unstable flows, such as the frequency lock-in phenomenon in the transonic buffet flow. The underlying mechanism is the instability characteristic of the system that becomes more complex, namely, further instability on the structural mode because
Chuanqiang Gao, Weiwei Zhang, Xintao Li
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Using Non-Normality for Passive Laminar Flow Control

2008
The scope of this paper was to show how optimal transient growth due to non-normality can be used as an effective amplifier of a passive laminar flow control. Optimal perturbations, usually seen as the most dangerous for transition are here seen as the most effective for control.
C. Cossu, L. Brandt, J. H. M. Fransson, TALAMELLI, ALESSANDRO   +3 more
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Turbulent flow separation control through passive techniques

2nd Shear Flow Conference, 1989
Several passive separation control techniques for controlling moderate two-dimensional turbulent flow separation over a backward-facing ramp are studied. Small transverse and swept grooves, passive porous surfaces, large longitudinal grooves, and vortex generators were among the techniques used. It was found that, unlike the transverse and longitudinal
J. LIN, F. HOWARD, G. SELBY
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Passive Control of Pressure Fluctuations Generated by Separated Flow

AIAA Journal, 1996
Measurements of wall-pressure fluctuations have been made in the flow behind a backward-facing step, with a permeable reattachment surface Different configurations are tried, the most successful producing a reduction in peak rms pressure fluctuation of about 13% and a reduction in drag of about 9%.
A. F. Heenan, J. F. Morrison
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Passive Control of Flow Induced Vibrations by Splitter Blades

Volume 2: Combustion and Fuels; Oil and Gas Applications; Cycle Innovations; Heat Transfer; Electric Power; Industrial and Cogeneration; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; IGTI Scholar Award, 1993
Splitter blades as a passive control technique for flow induced vibrations is investigated by developing an unsteady aerodynamic model to predict the effect of incorporating splitter blades into the design of an axial flow blade row operating in an incompressible flow field.
H. W. D. Chiang, S. Fleeter
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Flow Control of Jet Flow by Passive Nozzle Configuration Changes

International Journal of Flow Control, 2009
Nozzle configuration may offer the possibility of a passive control technique to provide high mixing and heat transfer rates. Thus, numbers of investigations have been carried out to reveal the influence of nozzle configuration on the flow characteristics. However, very few papers in the scientific literature have focused on orifice jets.
null Shakouchi, null Kito, null Sakamoto, null Tsujimoto, null Ando   +4 more
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Flow around a semicircular cylinder with passive flow control mechanisms

Experiments in Fluids, 2017
Wind tunnel experiments were performed to study the effect of passive flow control strategies on the wake and drag of a semicircular cylinder of infinite aspect ratio. High-resolution planar particle image velocimetry was used to obtain flow statistics around the semicircular cylinder at Reynolds number
A. M. Hamed, J. Vega, B. Liu, L. P. Chamorro   +3 more
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Passive Multiscale Flow Control by Fractal Grids

2008
Wind tunnel grid-generated turbulence based on a fractal square motif has been studied via hot-wire anemometry, at several free-stream velocities. The aim of the exercise was to see whether a fractal motif could enable multiscale flow control such that the ‘objective functions’ are the nature of the turbulence decay and its non-dimensional turbulence ...
R. E. E. Seoud, J. C. Vassilicos
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