Identification of Eighteen Flutter Derivatives

摘要

The prediction of flutter instability is of major concern for design of flexible structures. This necessitates the identification of aeroelastic parameters known as flutter derivatives from wind tunnel experiments. The extraction of flutter derivatives using a section model becomes more challenging when the number of degrees of freedom (DOF) increases from two to three. Work in the field of identifying all the eighteen flutter derivatives using section models with all three-DOF has been limited. This motivated the development of a new system identification method to efficiently extract all the eighteen flutter derivatives using a three-DOF section model. Numerical simulations were done to validate the efficiency of ILS method. A versatile three-DOF elastic suspension system was built and used for wind tunnel testing. To demonstrate this technique, all eighteen flutter derivatives for an airfoil section model were identified. The authenticity of a particular flutter derivative was determined by comparing the results obtained from all possible DOF combinations.