Based on the fan self-noise empirical prediction model developed by Gliebe and the turbulence -blade interaction noise analytical prediction model developed by Mugridge-Morfey and using GE R4 Fan for study

a detailed analysis of fan self-noise and rotor wake turbulence-OGV (outlet guide vane) interaction broadband noise (turbulence interaction noise) characteristics is performed. Different fan design parameters and different turbulence parameters' effects on the fan self-noise and turbulence interaction noise is investigated. Calculation results show that turbulence interaction noise dominates the fan broadband noise. Turbulence interaction noise is about 6-10dB higher than rotor self-noise and about 20dB higher than outlet guide vane self-noise. In addition

the incoming flow velocity of OGV plays the most important role in turbulence interaction noise and 15% increase of the velocity can lead to an increased sound power of about 4dB. The turbulence intensity has relatively important effects on the turbulence interaction noise and 30% increase of turbulence intensity can result in about 1.5dB higher sound power.