Evaluation of tonal aeroacoustic sources in subsonic fans using inverse models.

The article reports on the proposed method that attempts to quantify the acoustically radiating modes of the blade unsteady lift and inflow velocity in the circumferential spectral domain. The method is based on the inversion of the Blake model for tonal noise from subsonic fans. It cites the need for one experimental case to demonstrate the capability of the inverse model to qualitatively reconstruct the blade loading and inflow velocity variations of an automotive engine cooling fan.