Unstructured Euler flutter analysis of two-dimensional wing-tail configuration

1995 ◽  
Vol 32 (5) ◽  
pp. 1152-1155 ◽  
Author(s):  
Dartzi Pan ◽  
Jen-Chieh Cheng
Keyword(s):  
Two Dimensional ◽  
Flutter Analysis

Robust Flutter Analysis of an Airfoil with Flap Freeplay Uncertainty

2008 ◽  
Vol 33-37 ◽  
pp. 1247-1252 ◽  
Author(s):  
Zhi Chun Yang ◽  
Ying Song Gu
Keyword(s):  
Control Surface ◽  
Two Dimensional ◽  
Advanced Technique ◽  
Worst Case ◽  
Wing Model ◽  
Freeplay Nonlinearity ◽  
Flutter Analysis ◽  
Flutter Boundary ◽  
Nominal Parameter ◽  
Flutter Margin

Modern robust flutter method is an advanced technique for flutter margin estimation. It always gives the worst-case flutter speed with respect to potential modeling errors. Most literatures are focused on linear parameter uncertainty in mass, stiffness and damping parameters, etc. But the uncertainties of some structural nonlinear parameters, the freeplay in control surface for example, have not been taken into account. A robust flutter analysis approach in μ-framework with uncertain nonlinear operator is proposed in this study. Using describing function method the equivalent stiffness formulation is derived for a two dimensional wing model with freeplay nonlinearity in its flap rotating stiffness. The robust flutter margin is calculated for the two dimensional wing with flap freeplay uncertainty and the results are compared with that obtained with nominal parameter values. It is found that by considering the perturbation of freeplay parameter more conservative flutter boundary can be obtained, and the proposed method in μ-framework can be applied in flutter analysis with other types of concentrated nonlinearities.

Flutter analysis of cascades using a two dimensional Euler solver

1991 ◽  
Author(s):  
T. REDDY ◽  
MILIND BAKHLE ◽  
DENNIS HUFF ◽  
TIMOTHYW. SWAFFORD
Keyword(s):  
Two Dimensional ◽  
Flutter Analysis ◽  
Euler Solver

scholarly journals Extension of dual equivalent linearization technique to flutter analysis of two dimensional nonlinear airfoils

2015 ◽  
Vol 37 (3) ◽  
pp. 217-230 ◽  
Author(s):  
Nguyen Minh Triet
Keyword(s):  
Numerical Calculation ◽  
Equivalent Linearization ◽  
Nonlinear Stiffness ◽  
Two Dimensional ◽  
Local Approach ◽  
Linearization Technique ◽  
Flutter Analysis ◽  
Local Equivalent ◽  
Stiffness And Damping ◽  
Linearization Coefficients

This paper extends the dual equivalent linearization  technique (ELT) to obtain flutter speeds of a two-dimensional airfoil  with nonlinear stiffness and damping in pitch degree of freedom.  Although the use of dual ELT has been investigated in some previous papers,  this paper presents an extension of dual ELT using the global-local  approach, in which the local equivalent linearization coefficients are averaged in the  global sense. The numerical calculation shows that the extended dual ELT  gives more accurate flutter speeds in comparison with the ones of classical  ELT.

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