Analytical solution for sound radiated from the rotating point source in uniform subsonic axial flow

The paper presents an analytical solution for sound radiated from the rotating monopole and dipole point sources in uniform subsonic axial flow by employing the spherical harmonic series expansion method. The analytical results obtained from the present series expansion formulations have a good agreement with the numerical results obtained from the time-domain and frequency-domain numerical methods. The results also indicate that the effect of the freestream Mach number on the directivity pattern is various for different types of the rotating sources.