Sub-Scale Demonstration of the Active Feedback Control of Gas-Turbine Combustion Instabilities

2000 ◽  
Vol 122 (2) ◽  
pp. 262-268 ◽  
Author(s):  
Stanley S. Sattinger ◽  
Yedidia Neumeier ◽  
Aharon Nabi ◽  
Ben T. Zinn ◽  
David J. Amos ◽  
...  
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Gas Turbine ◽  
Active Control ◽  
Combustion Instabilities ◽  
Engine Operation ◽  
Turbine Engine ◽  
Control Approach ◽  
Active Feedback ◽  
Active Feedback Control

Described are sub-scale tests that successfully demonstrate active feedback control as a means of suppressing damaging combustion oscillations in natural-gas-fueled, lean-premix combustors. The control approach is to damp the oscillations by suitably modulating an auxiliary flow of fuel injected near the flame. The control system incorporates state observer software that can ascertain the frequency, amplitude, and phase of the dominant modes of combustion oscillation, and a sub-scale fuel flow modulator that responds to frequencies well above 1 kHz. The demonstration was conducted on a test combustor that could sustain acoustically coupled combustion instabilities at preheat and pressurization conditions approaching those of gas-turbine engine operation. With the control system inactive, two separate instabilities occurred with combined amplitudes of pressure oscillations exceeding 70 kPa (10 psi). The active control system produced four-fold overall reduction in these amplitudes. With the exception of an explainable control response limitation at one frequency, this reduction represented a major milestone in the implementation of active control. [S0742-4795(00)00702-X]

scholarly journals Sub-Scale Demonstration of the Active Feedback Control of Gas-Turbine Combustion Instabilities

1998 ◽  
Author(s):  
Stanley S. Sattinger ◽  
Yedidia Neumeier ◽  
Aharon Nabi ◽  
Ben T. Zinn ◽  
David J. Amos ◽  
...  
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Gas Turbine ◽  
Active Control ◽  
Combustion Instabilities ◽  
Engine Operation ◽  
Turbine Engine ◽  
Control Approach ◽  
Active Feedback ◽  
Active Feedback Control

Described are sub-scale tests that successfully demonstrate active feedback control as a means of suppressing damaging combustion oscillations in natural-gas-fueled, lean-premix combustors. The control approach is to damp the oscillations by suitably modulating an auxiliary flow of fuel injected near the flame. The control system incorporates state observer software that can ascertain the frequency, amplitude, and phase of the dominant modes of combustion oscillation, and a sub-scale fuel flow modulator that responds to frequencies well above 1 kHz. The demonstration was conducted on a test combustor that could sustain acoustically coupled combustion instabilities at preheat and pressurization conditions approaching those of gas-turbine engine operation. With the control system inactive, two separate instabilities occurred with combined amplitudes of pressure oscillations exceeding 70 kPa (10 psi). The active control system produced four-fold overall reduction in these amplitudes. With the exception of an explainable control response limitation at one frequency, this reduction represented a major milestone in the implementation of active control.

Smart Combustors: Just Around the Corner

2005 ◽  
Author(s):  
Ben T. Zinn
Keyword(s):  
Control System ◽  
Control Systems ◽  
Gas Turbine ◽  
Active Control ◽  
Health Monitoring ◽  
State Of The Art ◽  
The State ◽  
Research Needs ◽  
Combustion Instabilities ◽  
Lean Blowout

This paper reviews the state of the art of active control systems (ACS) for gas turbine combustors. Specifically, it discusses the manner in which ACS can improve the performance of combustors, the architecture of such ACS, and the designs and promising performance of ACS that have been developed to control combustion instabilities, lean blowout and pattern factor. The paper closes with a discussion of research needs, with emphasis on the integration of utilized engine ACS, health monitoring and prognostication systems into a single control system that could survive in the harsh combustor environment.

Active feedback control of elastic wave metamaterials

2017 ◽  
Vol 28 (15) ◽  
pp. 2110-2116 ◽  
Author(s):  
Yi-Ze Wang ◽  
Feng-Ming Li ◽  
Yue-Sheng Wang
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Elastic Wave ◽  
Effective Mass ◽  
Stop Band ◽  
Acoustic Properties ◽  
System Stability ◽  
Negative Effective Mass ◽  
Active Feedback ◽  
Active Feedback Control

As an important extension of periodic structures and phononic crystals, elastic wave/acoustic metamaterials can show negative effective parameters for special frequency regions. Although the active control method is widely applied to the vibration isolation and elastic wave propagation, little attention has been paid on changing elastic wave/acoustic properties of metamaterials. In this work, a new kind of elastic wave metamaterials combined with the automatic control system is presented. Propagation behaviors of the elastic wave are discussed. To demonstrate the effect of the active feedback control, the stop band properties, tunable negative effective mass and control system stability are considered. The results show that the negative acceleration feedback control can enhance the frequency region that creates the negative effective mass. Moreover, the stability of this periodic structure can be achieved.

Active Sloshing Control by Using Movable Plates Device Based on Flow Control Method

2009 ◽  
Author(s):  
Kensuke Hara ◽  
Masahiro Watanabe ◽  
Kazuki Hirai
Keyword(s):  
Surface Wave ◽  
Feedback Control ◽  
Flow Pattern ◽  
Active Control ◽  
Present Method ◽  
Control Method ◽  
Movable Plate ◽  
Visualization Experiment ◽  
Active Feedback ◽  
Active Feedback Control

This paper deals with an experimental study of an active control technique for the suppression of sloshing based on flow control in the tank. In this paper, we proposed the active feedback control method by using movable plates which are set in liquid. In the experiment, the present method is applied to the 2-dimensional problem of sloshing which occurs in the rectangular tank due to a horizontal excitation. The sloshing are suppressed by the active feedback to the rotation of the movable plate installed in liquid. The suppression performances are examined by changing the phase difference between the control signal of rotation angles of the movable plate and the liquid surface displacement (phase-shift). The performance of proposed method is evaluated by the time history, the root mean square value and frequency-response of the surface wave displacement under the active feedback control. Moreover, the effects of movable plate number and installation position on the suppression performance are clarified. On the other hand, the visualization experiment is conducted to obtain the flow pattern in the tank when the sloshing is controlled by the present method. The decreasing mechanism of the surface wave is discussed by the result of the visualization experiment. As a result, it is shown that the proposed control devics and active control method suppress the sloshing effectively. Furthermore, it is found that the changes of flow pattern by the drive of movable plate cause the suppression of sloshing in the visualization experiment.

scholarly journals Sound Transmission Comparisons of Active Elastic Wave Metamaterial Immersed in External Mean Flow

2021 ◽  
Author(s):  
Zhi-Hua He ◽  
Yi-Ze Wang ◽  
Yue-Sheng Wang
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Elastic Wave ◽  
Sound Transmission ◽  
Feedback Control System ◽  
Mean Flow ◽  
Transmission Properties ◽  
Active Feedback ◽  
Active Feedback Control ◽  
Equivalent Method

AbstractUsing the active feedback control system on the elastic wave metamaterial, this research concentrates on the sound transmission with the dynamic effective model. The metamaterial is subjected to an incident pressure and immersed in the external mean flow. The elastic wave metamaterial consists of double plates and the upper and lower four-link mechanisms are attached inside. The vertical resonator is attached by the active feedback control system and connected with two four-link mechanisms. Based on the dynamic equivalent method, the metamaterial is equivalent as a single-layer plate by the dynamic effective parameter. With the coupling between the fluid and structure, the expression of the sound transmission loss (STL) is derived. This research shows the influence of effective mass density on sound transmission properties, and the STL in both modes can be tuned by the acceleration and displacement feedback constants. In addition, the dynamic response and the STL are also changed obviously by different values of structural damping, incident angle (i.e., the elevation and azimuth angles) and Mach number of the external fluid with the mean flow property. The results for sound transmission by two methods are compared, i.e., the virtual work principle for double plates and the dynamic equivalent method corresponding to a single one. This paper is expected to be helpful for understanding the sound transmission properties of both pure single- and double-plate models.

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