TONAL NOISE GENERATION IN AN INLET VANED AXIAL BLOWER AT SEVERAL AXIAL GAPS

摘要

The main objective is the numerical study of the noise generation in a single stage axial flow blower. For the present work, just the discrete noise generation (tonal noise) is dealt with. A numerical methodology based on a generalization of Lighthill's aero-acoustic analogy, the so-called Ffowcs Williams and Hawkings aero-acoustic analogy (FFWH), is developed. The numerical methodology has been tested with two different operational configurations of the blower: a first one, with a reduced axial gap between the rows of the stage (i.e. 50 mm) and a second one with a higher axial distance (i.e. 70 mm). The specific contribution of every tonal noise source term will be analyzed for both configurations.