Abstract
Effects of a volute angle of scroll casing were investigated relating to the characteristics of aerodynamics and noise of a multi-blade sirocco fan with forward swept blades. It was shown that in the aerodynamic characteristics, the optimal volute angle existed between 4.8 and 7.2 degrees, and in the characteristics of noise, that existed in the near 7.2 degrees. Using the method of formulae to estimate the turbulent noise which we proposed in this paper, the sound pressure level can be predicted with the accuracy of about ±3dB within these experiments.
