3-D Prototypical Aeroelastic Wing Section with Structural Nonlinearity

2002 ◽  
Vol 8 (5) ◽  
pp. 553-573 ◽  
Author(s):  
Jeonghwan Ko ◽  
Thomas W. Strganac ◽  
John L. Junkins ◽  
Maruthi R. Akella ◽  
Andrew J. Kurdila

The recently derived structured model reference adaptive control (SMRAC) method is considered for the active suppression of limit cycle oscillations for a typical wing section with a structural nonlinearity. The SMRAC method uses the specific structure of the equations of motion governing general mechanical systems. This adaptive control method is implemented and tested in wind tunnel experiments to validate the performance. For comparison, results obtained with adaptive feedback linearization are also presented. It is shown that the derived SMRAC is advantageous in that it suppresses limit cycle oscillations at higher velocities, and also it can rigorously treat actuator saturation a priori.


2019 ◽  
Vol 19 (02) ◽  
pp. 1950013 ◽  
Author(s):  
A. S. Mirabbashi ◽  
A. Mazidi ◽  
M. M. Jalili

In this paper, both experimental and analytical flutter analyses are conducted for a typical 5-degree of freedon (5DOF) wing section carrying a flexibly mounted unbalanced engine. The wing flexibility is simulated by two torsional and longitudinal springs at the wing elastic axis. One flap is attached to the wing section by a torsion spring. Also, the engine is connected to the wing by two elastic joints. Each joint is simulated by a spring and damper unit to bring the model close to reality. Both the torsional and longitudinal motions of the engine are considered in the aeroelastic governing equations derived from the Lagrange equations. Also, Peter’s finite state model is used to simulate the aerodynamic loads on the wing. Effects of various engine parameters such as position, connection stiffness, mass, thrust and unbalanced force on the flutter of the wing are investigated. The results show that the aeroelastic stability region is limited by increasing the engine mass, pylon length, engine thrust and unbalanced force. Furthermore, increasing the damping and stiffness coefficients of the engine connection enlarges the stability domain.


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