UNSTEADY AERODYNAMIC PREDICTION METHODS APPLIED IN AEROELASTICITY.

A brief survey is presented of the basic prediction methods in unsteady aerodynamics needed in aeroelasticity. After an introductory outline of some of the most important aeroelastic phenomena, some representative concepts applied to calculate unstead aerodynamic forces in subsonic and supersonic flow are described. Attention is then given to areas which are not yet adequately covered by the presently existing theories and which comprise effects of gap geometry between fixed wing and control surfaces, effects of mean incidence about which a wing or control surface is oscillating, effect of wing thickness, Reynolds number, etc. Furthermore, some not yet published results related to interfering multiple lifting configurations are presented. These results include thrust calculations on oscillating tandem wings in incompressible flow, wing-induced unsteady tail loads, and some downwash evaluations behind wings in supersonic flow.