Figures of the Article

• Schematic of the CFD/vortex particle coupling zone
• Thrust time history of the C-T rotor in the numerical simulation
• Typical instantaneous flow fields around the rotor in the deep vortex ring state(${\mu }_{z}=1.2$)
• Four spanwise cross sections along the rotor blade
• Variation of lift coefficient at four blade sections under different vertical descent rates
• Schematic of the observation point locations
• Loading noise radiation under different flight states
• Loading noise characteristics under different flight conditions (peak noise location)
• Loading noise characteristics under different flight conditions (endpoint location)
• Time history of loading noise pressure at different observation points in the vortex ring state
• Spectral analysis result for the loading noise at different observation points in the vortex ring state
• Schematic of microphone installation on the helicopter