[en] The nonlinear Source and Doublet Panel Method (SDPM) makes use of the nonlinear form of the unsteady Bernoulli equation, which can be expanded as a polynomial series of the square of the flow velocities on the surface. Applying the Fourier Transform to such expansions and carrying out the necessary convolutions leads to an expression for the first harmonic of the pressure distribution that is a linear function for the flow velocities and can be used for linear flutter analysis. In the presence of structural nonlinearity, the response of the aircraft's structure can be a limit cycle oscillation whose amplitude increases as the free stream airspeed varies. The present work aims to develop a Harmonic Balance scheme for predicting these oscillations that makes use of the higher frequency components of the pressure distribution calculated using the SDPM and is written entirely in the frequency domain.
