エッジトーン周波数特性の数値シミュレーション

抄録

An Edge tone is self-excited sound, which is one of the important subsonic aerodynamic noises. This Edge tone problem phenomenon is computationally simulated using the two-dimensional compressible Navier-Stokes equations. The distance from the slit to the edge is changed with the jet speed and the slit width being kept constant. Acoustic waves having dipole characteristics are well simulated which shows edge tone mechanism is easily captured. FFT analysis shows that the frequency jumps agrees with the Brown's empirical formula. The frequency of the edge tone is influenced by the distance from the slit to the edge. The result indicates that the numerical approach presented is useful and become a good research tool for understanding if the acoustics problem.