Efficient Frequency-Domain Aeroacoustic Simulation of Gust Response Using Harmonic Balance Method

Periodic unsteady flow problems often exhibit computational inefficiency when conventional time-domain methods are employed. This phenomenon can be attributed to the lengthy transition phase before reaching the ultimate periodic state. To address this problem, the harmonic balance method (HBM) is employed for aeroacoustic applications through the implementation of convective monopole sources, frequency-domain gust excitation, and nonreflective boundary conditions. A set of test cases is considered to evaluate this method, including monopole sources with uniform background flows, the pitching oscillations of airfoils, leading-edge noise of gust–airfoil interactions, and the response of gust–cascade interactions. The results show good agreement with analytical and experimental data, with normalized root-mean-square errors typically below 10% across most considered cases. The findings from this research demonstrate a comprehensive range of potential applications for HBM in the fields of fluid dynamics and aeroacoustics.