Effects of a Cavity Flow Passive Control on Optical Phase Degradations

2005 ◽  
Author(s):  
R. Deron ◽  
H. Illy ◽  
P. Geffroy ◽  
F. Mendez ◽  
B. Corbel
Keyword(s):  
Passive Control ◽  
Cavity Flow ◽  
Optical Phase

scholarly journals Effects of Active and Passive Control Techniques on Mach 1.5 Cavity Flow Dynamics

2017 ◽  
Vol 2017 ◽  
pp. 1-24
Author(s):  
Selin Aradag ◽  
Kubra Asena Gelisli ◽  
Elcin Ceren Yaldir
Keyword(s):  
Passive Control ◽  
Control Method ◽  
Pressure Fluctuations ◽  
Leading Edge ◽  
Cavity Flow ◽  
Flow Dynamics ◽  
Cover Plate ◽  
Control Methods ◽  
Trailing Edge ◽  
Control Techniques

Supersonic flow over cavities has been of interest since 1960s because cavities represent the bomb bays of aircraft. The flow is transient, turbulent, and complicated. Pressure fluctuations inside the cavity can impede successful weapon release. The objective of this study is to use active and passive control methods on supersonic cavity flow numerically to decrease or eliminate pressure oscillations. Jet blowing at several locations on the front and aft walls of the cavity configuration is used as an active control method. Several techniques are used for passive control including using a cover plate to separate the flow dynamics inside and outside of the cavity, trailing edge wall modifications, such as inclination of the trailing edge, and providing curvature to the trailing edge wall. The results of active and passive control techniques are compared with the baseline case in terms of pressure fluctuations, sound pressure levels at the leading edge, trailing edge walls, and cavity floor and in terms of formation of the flow structures and the results are presented. It is observed from the results that modification of the trailing edge wall is the most effective of the control methods tested leading to up to 40 dB reductions in cavity tones.

416 Passive Control of Supersonic Cavity Flow Using Sub-Cavity(2)

2007 ◽  
Vol 2007 (0) ◽  
pp. _416-1_-_416-4_
Author(s):  
Shigeru MATSUO ◽  
Kenbu TERAMOTO ◽  
Shinya NAKANO ◽  
Toshiaki SETOGUCHI
Keyword(s):  
Passive Control ◽  
Cavity Flow ◽  
Supersonic Cavity

416 Passive Control of Supersonic Cavity Flow Using Sub-Cavity(1)

2007 ◽  
Vol 2007 (0) ◽  
pp. _416-a_
Author(s):  
Shigeru MATSUO ◽  
Kenbu TERAMOTO ◽  
Shinya NAKANO ◽  
Toshiaki SETOGUCHI
Keyword(s):  
Passive Control ◽  
Cavity Flow ◽  
Supersonic Cavity

Passive Control Techniques to Alleviate Supersonic Cavity Flow Oscillation

2008 ◽  
Vol 24 (4) ◽  
pp. 697-703 ◽  
Author(s):  
Youngki Lee ◽  
Minsung Kang ◽  
Heuydong Kim ◽  
Toshiaki Setoguchi
Keyword(s):  
Passive Control ◽  
Cavity Flow ◽  
Flow Oscillation ◽  
Control Techniques ◽  
Supersonic Cavity

Passive Control of Transonic Cavity Flow

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
David G. MacManus ◽  
Diane S. Doran
Keyword(s):  
High Speed ◽  
Passive Control ◽  
Noise Suppression ◽  
Flow Behavior ◽  
Leading Edge ◽  
Cavity Flow ◽  
Step Length ◽  
Geometric Feature ◽  
Sufficient Intensity ◽  
Grazing Flow

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 require costly feedback control systems or entail other drawbacks such as drag penalties or rapid performance degradation at off-design condition. The current study focuses on the use of simple geometric modifications of a rectangular planform cavity with the aim of attenuating the aeroacoustic signature. Experiments were performed in an intermittent suck-down transonic wind tunnel by using a typical open flow rectangular planform cavity, which was modularly designed such that the leading and trailing edge geometries could be modified by using a family of inserts. The current work focused on a variety of recessed leading edge step arrangements. Configurations were tested at transonic Mach numbers spanning the range Mach 0.7–0.9, and unsteady pressure measurements were recorded at various stations within the cavity in order to obtain acoustic spectra. The most effective configuration at Mach 0.9 was the leading edge step employing a step height to step length ratio of 0.4. This configuration achieved a tonal attenuation of up to 18.6dB and an overall sound pressure level (OASPL) reduction of approximately 7.5dB. This is a significant level of noise suppression in comparison with other passive control methods. In addition, it offers the additional benefits of being a simple geometric feature, which does not rely on placing flow effectors into the high-speed grazing flow.

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