Performance Comparison Between Piezoelectrically Induced Stresses and Active Control for Aeroelastic Stability Augmentation

AIAA Journal ◽  
2021 ◽  
pp. 1-17
Author(s):  
Thiago de Souza Siqueira Versiani ◽  
Rafael Mendes Bertolin ◽  
Maurício Vicente Donadon ◽  
Flávio José Silvestre
Keyword(s):  
Active Control ◽  
Performance Comparison ◽  
Aeroelastic Stability ◽  
Stability Augmentation ◽  
Induced Stresses

Control of Vibration Using Compliant Actuators

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Sannia Mareta ◽  
Dunant Halim ◽  
Atanas A. Popov
Keyword(s):  
Vibration Control ◽  
Active Control ◽  
Passive Control ◽  
Performance Comparison ◽  
Control Performance ◽  
Frequency Bandwidth ◽  
Series Configuration ◽  
Compliant Actuators ◽  
Stiffness And Damping ◽  
Compliant Actuator

This work proposes a method for controlling vibration using compliant-based actuators. The compliant actuator combines a conventional actuator with elastic elements in a series configuration. The benefits of compliant actuators for vibration control applications, demonstrated in this work, are twofold: (i) vibration reduction over a wide frequency bandwidth by passive control means and (ii) improvement of vibration control performance when active control is applied using the compliant actuator. The vibration control performance is compared with the control performance achieved using the well-known vibration absorber and conventional rigid actuator systems. The performance comparison showed that the compliant actuator provided a better flexibility in achieving vibration control over a certain frequency bandwidth. The passive and active control characteristics of the compliant actuator are investigated, which shows that the control performance is highly dependent on the compliant stiffness parameter. The active control characteristics are analyzed by using the proportional-derivative (PD) control strategy which demonstrated the capability of effectively changing the respective effective stiffness and damping of the system. These attractive dual passive–active control characteristics are therefore advantageous for achieving an effective vibration control system, particularly for controlling the vibration over a specific wide frequency bandwidth.

scholarly journals An Experimental Evaluation of Generalized Predictive Control for Tiltrotor Aeroelastic Stability Augmentation in Airplane Mode of Flight

2002 ◽  
Vol 47 (3) ◽  
pp. 198-208 ◽  
Author(s):  
Raymond G. Kvaternik ◽  
David J. Piatak ◽  
Mark W. Nixon ◽  
Chester W. Langston ◽  
Jeffrey D. Singleton ◽  
...  
Keyword(s):  
Predictive Control ◽  
Experimental Evaluation ◽  
Generalized Predictive Control ◽  
Aeroelastic Stability ◽  
Stability Augmentation

A Numerical Study on Active Control for Tiltrotor Whirl Flutter Stability Augmentation

2006 ◽  
Vol 51 (3) ◽  
pp. 244 ◽  
Author(s):  
Joerg P. Mueller ◽  
Yves Gourinat ◽  
Rogelio Ferrer ◽  
Tomasz Krysinski ◽  
Benjamin Kerdreux
Keyword(s):  
Active Control ◽  
Numerical Study ◽  
Stability Augmentation ◽  
Whirl Flutter

Influence of Acoustic Blockage on Flutter Instability in a Transonic Nozzle

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Quentin Rendu ◽  
Yannick Rozenberg ◽  
Stéphane Aubert ◽  
Pascal Ferrand
Keyword(s):  
Active Control ◽  
Separated Flow ◽  
Compressor Blade ◽  
Navier Stokes ◽  
Pressure Waves ◽  
Aeroelastic Stability ◽  
Design And Optimization ◽  
Flutter Instability ◽  
Unstable Configuration ◽  
Low Amplitude

In order to predict oscillating loads on a structure, time-linearized methods are fast enough to be routinely used in design and optimization steps of a turbomachine stage. In this work, frequency-domain time-linearized Navier–Stokes computations are proposed to predict the unsteady separated flow generated by an oscillating bump in a transonic nozzle. The influence of regressive pressure waves on the aeroelastic stability is investigated. This case is representative of flutter of a compressor blade submitted to downstream stator potential effects. The influence of frequency is first investigated on a generic oscillating bump to identify the most unstable configuration. Introducing backward traveling pressure waves, it is then showed that aeroelastic stability of the system depends on the phase shift between the wave's source and the bump motion. Finally, feasibility of active control through backward traveling pressure waves is evaluated. The results show a high stabilizing effect even for low amplitude, opening new perspectives for the active control of choke flutter.

Morphologies of Nonadherent Al2O3 and Matching Substrate Surfaces

1972 ◽  
Vol 30 ◽  
pp. 524-525
Author(s):  
C. S. Giggins ◽  
J. K. Tien ◽  
B. H. Kear ◽  
F. S. Pettit
Keyword(s):  
Electron Microscopy ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
Substrate Surface ◽  
Morphological Features ◽  
Thermally Induced ◽  
Oxide Spallation ◽  
Oxidation Resistant ◽  
Induced Stresses ◽  
Substrate Surfaces

The performance of most oxidation resistant alloys and coatings is markedly improved if the oxide scale strongly adheres to the substrate surface. Consequently, in order to develop alloys and coatings with improved oxidation resistance, it has become necessary to determine the conditions that lead to spallation of oxides from the surfaces of alloys. In what follows, the morphological features of nonadherent Al2O3, and the substrate surfaces from which the Al2O3 has spalled, are presented and related to oxide spallation.The Al2O3, scales were developed by oxidizing Fe-25Cr-4Al (w/o) and Ni-rich Ni3 (Al,Ta) alloys in air at 1200°C. These scales spalled from their substrates upon cooling as a result of thermally induced stresses. The scales and the alloy substrate surfaces were then examined by scanning and replication electron microscopy.The Al2O3, scales from the Fe-Cr-Al contained filamentary protrusions at the oxide-gas interface, Fig. 1(a). In addition, nodules of oxide have been developed such that cavities were formed between the oxide and the substrate, Fig. 1(a).

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