The invention discloses a helicopter ducted tail rotor noise reduction lining for low-frequency line spectrum noise suppression, and belongs to the technical field of helicopter ducted tail rotor noise reduction. Ducted tail rotor noise belongs to multi-line spectrum harmonic noise, and noise energy is reduced along with increase of frequency, that is, the noise energy is concentrated in first two-order harmonic waves. And on the other hand, the ducted tail rotor is low in rotating speed and small in blade number, so that the noise frequency is low. The micro-perforated plate composite folding back cavity is used as the sound absorption unit, and two sound absorption resonance frequencies of the sound absorption unit coincide with the first two orders of harmonic noise of the tail rotor through parameter design, so that the thickness of the whole sound absorption unit is reduced, and meanwhile, the low-frequency multi-line-spectrum noise reduction performance is achieved; the weight cost is reduced, and the tail rotor noise is effectively restrained.
本发明公开了一种面向低频线谱噪声抑制的直升机涵道尾桨降噪声衬,属于直升机涵道尾桨降噪技术领域,本发明涵道尾桨噪声属于多线谱谐波噪声,噪声能量随着频率的增加而降低,即噪声能量集中于前两阶谐波中。另一方面,涵道尾桨转速低、桨叶片数少,因此噪声频率较低。本发明中使用的微穿孔板复合折叠背腔作为吸声单元,通过参数设计使吸声单元的两个吸声共振频率与尾桨的前两阶谐波噪声重合,从而在降低了整体吸声单元的厚度同时还具备低频多线谱降噪性能,既减轻了重量代价又有效抑制了尾桨噪声。
Helicopter ducted tail rotor noise reduction lining for low-frequency line spectrum noise suppression
一种面向低频线谱噪声抑制的直升机涵道尾桨降噪声衬
2025-03-14
Patent
Electronic Resource
Chinese
TESTS OF THE HELICOPTER DUCTED TAIL ROTOR
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