Installation effects on propeller tone noise

The installation effects impose a distinct influence on the propeller noise characteristics. A simplified wing-propeller model with diverse installation positions were studied using unsteady numerical simulations to obtain the overall noise characteristics, component noise characteristics and key flow features under the take-off condition. The influence of installation locations on the propeller tone noise generation and radiation were analyzed. The results show that the installation effects lead to an increase of the thrust and maximum tone noise, and the direction of maximum tone noise moved upstream. The overlaid area between the propeller and the wing is the main region of wake-wing interaction, where the noise level is affected by Mach number, wake vorticity, wake-sweep region and so on. When the leading edge of the wing lies in the region with a horizontal distance of L = 0.5D and a vertical distance of H>0.3D, the installation effects can be weakened dramatically while the thrust can be still increased by 1%. The patterns of installation effect on propeller tone noise are identified from this research, which can be referred for low noise design of prop airplane.