Philip S. Beran, Bret K. Stanford, Kevin G. Wang
DOI Number: N/A
Conference number: IFASD-2017-016
A fast direct method was developed to compute flutter points and the sensitivities of these critical speeds to a wide range of aerodynamic and structural parameters. The method computes flutter sensitivities in an adjoint-based fashion to increase efficiency, and accounts for the dependence of flutter speed on the nonlinear relationship between static aeroelastic deformation and parameters of interest. This method is formulated as part of a general analysis framework, which is well-suited for prediction of Hopf bifurcation phenomena in a variety of nonlinear physical systems. The numerical properties of the scheme are studied using the problems of bifurcation of a tubular reactor and flutter of a very flexible, cantilevered wing. For the latter case, the wing is modeled structurally as a beam and discretized with finite elements; the aerodynamic loads are modeled with the ONERA stall model. Sensitivities of wing flutter speed with respect to a large number of aerodynamic and structural parameters are computed.