Periodic microstructure noise reduction device and noise suppression test system and method

The invention discloses a periodic microstructure noise reduction device and a noise suppression test system and method. The test system comprises a silencing wind tunnel, noise sensors and a model test piece. The model test piece adopts a periodic microstructure noise reduction device and is arranged in the silencing wind tunnel; the periodic microstructure noise reduction device comprises a reference cylinder, radial protruding structures are periodically arranged on the reference cylinder in the axial direction, the diameter of the reference cylinder is D, the length of the reference cylinder is L, the setting period is S, the outer diameter of each radial protruding structure is A, and the thickness of each radial protruding structure is B; and the plurality of noise sensors are arranged in the silencing wind tunnel in an arc-shaped array manner along the airflow direction by taking the center of the model test piece as a circle center. According to the test system provided by the invention, the noise gen