Critical Flutter Velocity Research Articles

Analytical Study of Suspension Bridge Flutter

A systematic procedure for investigating suspension bridge flutter is presented. As a prerequisite for flutter analysis the free vibration problem is considered first. The bridge is idealized as an initially stressed space structure and the natural frequencies and modes of oscillation are obtained as the solution to the eigenvalue problem associated with the system. The results of the free vibration problem are then used in connection with the results of recent wind tunnel techniques to investigate the flutter problem. The flutter equations of motion are formulated in terms of the flutter derivatives and the normal modes method is used to solve the resulting eigenvalue problem. The effect on the bridge stability of changing the major design parameters is investigated and the critical flutter velocity is plotted against the variation in the parameter investigated for each case.

Influence of the geometrical parameters of the profile and cascade on the critical flutter velocity of a pack of compressor blades

Influence of the geometrical parameters of the profile and cascade on the critical flutter velocity of a pack of compressor blades

Damping loss in a cascade of fluttering phased aerofoils

SummaryA study is made of the aerodynamic damping in a cascade of oscillating aerofoils in subsonic compressible flow with the system mode described by a constant interblade phasing predicted by Lane (9). The integral downwash equation is obtained as an extension of Possio's equation for an isolated aerofoil. Procedures for a practical solution of the equation have allowed the aerodynamic reactions and damping derivatives to be evaluated with a digital computer after minimisation of the critical flutter velocity with respect to interbiade phase angle. The effect of aerodynamic lag in separation conditions as a function of reduced frequency and chordwise location is compared with results without separation.

A Practical Approach to the Problem of Stall Flutter

Abstract A method is presented in this paper whereby the real part of the dynamic moment derivative may be obtained from a flutter test on a single blade oscillating in torsion alone in the stall region. These data may be used to predict the critical flutter velocity and frequency of a blade with the same geometrical properties oscillating with two degrees of freedom and having arbitrary elastic and inertial properties. It is possible that the present method can be used to predict the flutter speed and frequency of a cantilever blade by either a representative section or a Rayleigh-type analysis.