Acoustic liner, manufacturing method, power propulsion system and honeycomb core

Abstract

The invention relates to an acoustic liner, a manufacturing method, a power propulsion system and a honeycomb core. Wherein the acoustic liner comprises a perforated plate; the honeycomb core which comprises a plurality of honeycomb units which are separated from one another; and a back plate; the perforated plate is located at the top, the back plate is located at the bottom, and the honeycomb core is arranged between the perforated plate and the back plate to form a plurality of mutually separated resonant cavities with open tops and closed bottoms; each honeycomb unit comprises a plurality of honeycomb bodies distributed in the direction from the center to the periphery, each honeycomb body comprises a plurality of wall faces, and the bottoms of the wall faces are connected with the back plate and surround the center of the honeycomb unit in the circumferential direction; in two adjacent honeycomb bodies, the honeycomb body closer to the periphery surrounds the honeycomb body closer to the center; and at least two honeycomb bodies in the plurality of honeycomb bodies are different in height.

Description

technical field [0001] The invention relates to the field of acoustics, in particular to an acoustic lining and its manufacturing method, a power propulsion system and a honeycomb core for the acoustic lining. Background technique [0002] The problem of civil aircraft engine noise presents an important issue for the continuously growing air transport industry. The size of its noise level is directly related to the acquisition of the engine airworthiness visa. This is undoubtedly a huge challenge for the civil aviation engine being developed in our country. The noise level of large civil aircraft is one of the important contents of airworthiness certification. The noise certification standards are constantly changing with time. International Civil Aviation Organization (ICAO) Annex 16 has made detailed technical specifications for aircraft noise certification. This technology The specification adopts "Effective Perceived Noise Level" (EPNL) and considers three reference co...

AI Technical Summary

Problems solved by technology

However, with this structure, if the sound-absorbing frequency band needs to be further broadened, the number of layers of the honeycomb core needs to be further increased to increase the thickness of the acoustic lining, and the connection process between the multi-layer honeycomb core and the perforated plate is also relatively complicated. The structural strength of the lining is also difficult to guarantee

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