TABLE OF CONTENTS International Journal of Numerical Methods for Heat & Fluid Flow
Vol. 14 No. 4, 2004
Abstracts and keywords
L. Djayapertapa and C.B. Allen
Keywords Elasticity, Flight control, Flight dynamics, Aerodynamics
Transonic flutter and active flap control, in two dimensions, are simulated by coupling independent structural dynamic and inviscid aerodynamic models, in the time domain. A flight control system, to actively control the trailing edge flap motion, has also been incorporated and, since this requires perfect synchronisation of fluid, structure and control signal, the strong coupling approach is adopted. The computational method developed is used to perform transonic aeroelastic and aeroservoelastic calculations in the time domain, and used to compute stability (flutter) boundaries of 2D wing sections. Open and closed loop simulations show that active control can successfully suppress flutter and results in a significant increase in the allowable speed index in the transonic regime. It is also shown that active control is still effective when there is free-play in the control surface hinge. Flowfield analysis is used to investigate the nature of flutter and active control, and the fundamental importance of shock wave motion in the vicinity of the flap is demonstrated.
N. Qin, Y. Zhu and S.T. Shaw
Keywords Aerodynamics, Waveforms, Flow, Differential equations, Numerical analysis
In this paper, the effectiveness of a number of active devices for the control of shock waves on transonic aerofoils is investigated using numerical...
