To reduce noise from regional jet two-wheel main landing gear, a 10% scale wind tunnel model was fabricated and tested in a low-speed anechoic wind tunnel. Six types of noise reduction devices were prepared: a porous-plate cover around the tire axle and the lower half part of the strut, a plate between the mid door and strut, a plate on the side brace, wheel holes sealed with aluminum tape, a wind deflector and porous material with open cells affixed to the inner surfaces of the inboard gear door. In the wind tunnel test, significant noise reduction was achieved with the combination of the noise reduction devices except the wind deflector. Computational fluid dynamics simulations were also performed to see if they were able to predict the effect of the noise reduction devices with a reasonable amount of computational time, and to deepen understanding of their effect. Although the effect of the noise reduction in the computational result with the devices is smaller than the experimental result, their qualitative trends in the difference of the lowest noise configuration from the baseline configuration in sound pressure level and the polar directivity patterns at the mid-frequency range are similar.
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