Computation of Noise from the Internal Flow in a Centrifugal Fan

Abstract

The noise generated from the internal flow in a centrifugal fan was computed by computational aero-acoustics (CAA). The sound sources were obtained by large-eddy simulation (LES) of turbulent flow in the centrifugal fan. The computed sound pressure level (SPL) is better than the result by Curle’s equation below 300 Hz and agrees fairly well with the experimental data in this frequency range. Sound pressure level (SPL) is overpredicted at high frequency region. Fluid forces at the plane perpendicular to the axial direction play important roles on the peak of SPL at blade passing frequency (BPF) 600 Hz.