Experiments fulfiled in CETIM have shown that tonal blade-passing-frequency (BPF) noise becomes predominant for lawn-mowers with a big rotor diameter. 2-D and 3-D CFD unsteady computations give a clear picture of pseudo-sound perturbation inside the casing of lawn-mower. Method of representation of unsteady motion of compressible fluid with subsonic flow as a sum of vortex mode (pseudo-sound) and acoustical mode (airborne sound) is used to define the sound near field.
Serguei Timouchev, InteRe Co Ltd
Michael Bockhoff, Karine Mones, CETIM, Noise and Vibration Center
Andrey Aksenov, TESIS Ltd.
FAN NOIS 2003, International Symposium Senlis, 23-25, September 2003, Page 1/8