Computation Of Wing Flutter For Unsteady Transonic Flows In The Frequency Domain

Computation of wing flutter for unsteady transonic flows in the frequency domain is studied in this thesis. The wing is modeled structurally by vibrational modes, which are used as amplitude of motion by a finite element analysis. Conservative full - potential equation and three dimensional unsteady Euler equation are used to compute the unsteady transonic flows around airfoil and wings under simple harmonic motion. The full potential equation is solved by the time - accurate approximate factorization algorithm and internal Newton iterations, and the Euler equation by the finite - volume resolution scheme and dual - time stepping. The calculated aerodynamic forces are input to solve flutter equations, which are treated by V-g method of frequency domain. To a series of dampings, velocities and frequencies, the linear interpolation is applied and the flutter speed and flutter frequency are obtained. The calculated results of three dimensional unsteady flow and flutter have proved that the methods presented in the thesis are satisfactory.