A Slender Body Aeroelastic Transfer Function Including the Effects of Structural Flexibility and Nonstationary Aerodynamics

Citation

Schalin, Pehr Harald Benedictus (1955) A Slender Body Aeroelastic Transfer Function Including the Effects of Structural Flexibility and Nonstationary Aerodynamics. Engineer's thesis, California Institute of Technology. doi:10.7907/2GPJ-KV69. https://resolver.caltech.edu/CaltechETD:etd-12102003-114448

Abstract

On the basis of linearized nonstationary aerodynamics and a normal mode representation of the motion, the aeroelastic transfer functions of a symmetrically oscillating slender body are derived from energy principles. In the present analysis no structural damping or aerodynamic viscous forces are included, but they are believed not to alter the principal features of the system significantly. The aerodynamic force expressions, obtained as a side result, turn out to be exceedingly simple in the slender body case. The final eigenfrequency-analysis and the open loop frequency response of the system chosen in Appendix D indicate that the aerodynamic coupling is low. The eigenfrequencies therefore are accurately obtained from the simple decoupled equations. This also holds for the frequency response in a fairly wide band around each particular resonance frequency. The magnitude of the response of the elastic coordinates in comparison with rigid body responses at resonance frequencies clearly indicates the importance of elastic effects with respect to closed loop control problems.

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