Author details

From the wind-tunnel flutter testing it is observed that a moderate oscillation

A two-degree-of-freedom in transversal and rotational motions wing section for describing classical binary flutter mechanism is used to investigate the effect of free-play nonlinearity to the stability of the aero-elastic system and the associated limit cycles. The aerodynamic forces are calculated by using Theodorsen's method

By representing the aero-elastic system as a closed loop block diagrams of a dynamic system where the structural part serves as the main plant of the system and the aerodynamic transfer function as a feedback loop calculated based on the dynamic structural response, it is suitable to carry out the simulation on the platform of Simulink-Matlab. For this purpose the aerodynamic forces have to be

The work shows the effectiveness of the flow-structure interactions when the system is considered as a dynamic system where the response can be analysed in time domain and the effects of non-linear factors can be conveniently included

This research is funded by Ministry of Higher Education Malaysia under Funda-

The limit cycle oscillation and stability can be showed numerically by representing the phase portrait of the response. At the speed of airflow below the critical speed of flutter, a constant oscillation may happen due to a free-play nonlinearity. It can be shown that the stability boundary becomes smaller than the

mental Research Grant Scheme, no. FRGS/2/2013/TK09/02/1.

starts at 13 m/s flow speed and becomes severe vibration at 18 m/s. It can be concluded that a small free-play mechanism involves in the lower speed (less than the critical boundary), and a hardening-stiffness behaviour for the higher speed.

Phase portrait for the existence of 2° free-play mechanism in rotation at the wind speed of 14.0 m/s.

in frequency domain based on thin aerofoil theory.

Noise and Vibration Control - From Theory to Practice

4. Conclusion

Figure 14.

simultaneously.

critical speed.

148

Acknowledgements

conversed in Laplace domain.

Cosmas Pandit Pagwiwoko<sup>1</sup> and Louis Jezequel<sup>2</sup> \*

1 Faculty of Science and Engineering, Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham Malaysia, Selangor, Malaysia

2 Ecole Centrale de Lyon, Ecully, France

\*Address all correspondence to: louis.jezequel@ec-lyon.fr

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
