An engineering method suitable for blade vortex interaction(BVI) airload and acoustic analysis was established based on aerodynamic/elastic coupling. The aerodynamic model includes modified Beddoes wake method and CFD method. Acoustic prediction was based on FfowcsWilliams Hawkings(FWH) equation derived by acoustic analogy

and the elastic blade model was based on finite element method. By applying the established models

the airload and acoustic characteristics of rigid operational load survey(OLS) rotor were calculated under BVI flight state firstly

and the validity of the two aerodynamic models was compared

then the influences of elasticity and time step on HART Ⅱ rotor BVI airload and acoustic were analyzed. The results indicate that the time step adopted in BVI calculation should be no more than 2 degree. Peak acoustic pressure of OLS rotor predicted by CFD is only 60% of experimental data because of inherent numerical dissipation

while the modified Beddoes wake method can address this problem with high computation efficiency. Taking blade elasticity into consideration is beneficial for BVI acoustic prediction accuracy.