| Title |
Flow Induced Noise Characteristics of the Cross Flow Fan with Uniform/Random Pitch Blades |
| Keywords |
횡류홴 ; 날개 통과 주파수 ; 유동 소음 ; 이산 소음 ; 소음 ; 부등피치 ; Cross flow fan ; BPF ; Flow induced noise ; Discrete noise ; Noise ; Random pitch |
| Abstract |
The flow induced noise of the cross-flow fan with uniform/random pitch blades is predicted by computational methods. With the time dependent surface pressure data obtained by solving the incompressible Navier-Stokes equations in moving coordinates, the acoustic pressure is predicted by the Ffowcs Williams-Hawkings equation. The positions of the blade noise source are identified through an investigation of the acoustic pressure history induced by one blade, and it is confirmed that the dominant noise source is near the stabilizer. Since the acoustic pressure of the random pitch fan fluctuates according to the blade passing, the dominant BPF noise of the uniform pitch fan is modulated into some reduced discrete noises which have multiples of a 50 Hz difference from BPF. |