Turbulent Noise Generated by a Centrifugal Fan without Scroll Casing

An analytical treatment is proposed to estimating the sound pressure level of turbulent noise with L-weighting and A-weighting functions radiated by a centrifugal fan without scroll casing. In the theory of the turbulent noise, we assumed that the turbulent noise was generated by vortex shedding from the trailing edge and the vortex shed ding frequency, f, is correlated by the width at half depth of the wake. The agreement between the measured values and the predicted values of the width of wake and the mean relative velocity were satisfactory. The experimental values of the overall noise of L-weighting and A-weighting functions agreed well with the predicted values