scholarly journals Synthesis of an active flutter suppression system in the transonic domain using a computational model

2021 ◽  
pp. 1-19
Author(s):  
R. Vepa ◽  
J.R. Kwon

ABSTRACT Control laws for implementing active flutter suppression are generally derived from linear aeroelastic models. In this paper, families of control laws for implementing an active flutter suppression system were initially designed using linearised aeroelastic models based on the doublet lattice method after ignoring the aerodynamic loads associated with relatively faster time scales. Using these preliminary sets of control laws and the nonlinear transonic small disturbance theory, near-optimum control laws were chosen in the transonic domain to maximally increase the flutter speed of a typical aircraft wing by at least 16% or more. Thus it is shown that it is feasible to systematically design near-optimal control laws for active flutter suppression using computational models in transonic flow. The doublet lattice method coupled with the zeroth-order matrix Padé approximant provided the fastest method for synthesising a large number of preliminary control laws. The methodology was successfully demonstrated by applying it to two benchmarking examples.

2014 ◽  
Vol 898 ◽  
pp. 688-695
Author(s):  
Zhi Wei Sun ◽  
Jun Qiang Bai

A time-domain aeroservoelastic model is developed to calculate the flutter speed and an active flutter suppression system is designed by model predictive control. The finite-state, induced-flow theory and equilibrium beam finite element method are chosen to formulate the aeroservoelastic governing equations in state-space form, which is necessary for active flutter suppression design with modern control theory. A sensitivity analysis is performed to find the most appropriate number of induced-flow terms and beam elements. Model predictive control theory is adopted to design an active flutter suppression system due to its ability to deal with the constraints on rate change and amplitude of input. The numerical result shows a satisfactory precision of the flutter speed prediction, the close loop analysis shows that the flutter boundary is considerable expanded.


1986 ◽  
Vol 9 (1) ◽  
pp. 64-71 ◽  
Author(s):  
Bradley S. Liebst ◽  
William L. Garrard ◽  
William M. Adams

1981 ◽  
Vol 18 (7) ◽  
pp. 537-545 ◽  
Author(s):  
C. Hwang ◽  
E.H. Johnson ◽  
W.S. Pi

2012 ◽  
Vol 226-228 ◽  
pp. 64-69
Author(s):  
Ming Li Yu

The presented paper deals with the group delay in the digital filter induced instability of a two dimensional airfoil section active flutter suppression system. Firstly, the aeroelastic model of the airfoil with an ultrasonic motor actuated control surface is set up; secondly, both H∞and μ robust controllers are designed; and then, the group delay induced instability in wind tunnel test is presented; finally, through a combined theoretical and numerical study, the test phenomenon is well explained. Wind tunnel experiments and numerical simulations demonstrate that long enough group delay in digital filter can induce instability of flutter control system, the flutter under control will decrease first, and then become another flutter of lower frequency and moderated amplitude, and μ controller works better than H∞controller on the same condition.


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