A METHOD TO GENERATE THE SOURCE OF BUZZ-SAW NOISE GENERATED BY RANDOMLY STAGGERED ROTORS

摘要

A method to generate buzz-saw noise source is proposed to reduce the computational cost in modeling fan blades with random stagger angles. Considering a full annulus fan rotor with an arbitrary stagger angle on each blade, the multiple pure tone noise source is found to be able to be reconstructed from merely three steady simulations. The theoretical basis is, under the assumption of small stagger angles, the linear relation between the shock strength and the stagger angle. This method is applied on modified rotor of NASA rotor 67, pressure distribution on the reconstructed reference source plane is validated by simulation of the same modified rotor.