Acousti-Cap technology from Hexcel reduces noise in flight test

Hexcel (Stamford, CT, US), a global leader in advanced composite technology, announced on Sept. 6 that its Acousti-Cap broadband sound-reducing honeycomb, which enables engine designers to reduce the noise from takeoffs and landings yet without adding significant weight to the aircraft, was recently tested in a joint NASA-Boeing flight test on a B737 MAX test platform, and the results beat expectations as reported by Aviation Week.

The 2DOF (Two Degrees of Freedom) honeycomb core acoustic liner was introduced in 2008 and was subsequently adopted and installed on the Boeing 787 Dreamliner inlet, the Boeing 747-8 inlet and transcowl, and more recently on the Boeing 737 MAX inlet. This success enabled continued technology development and evolution in MDOF (Multi-Degrees of Freedom) where the acoustic septum is inserted in the honeycomb cell at different heights, as well as having two septums in honeycomb chambers. This type of technology allows for improved acoustic attenuation at a broader frequency range, as well as increased absorption. Collaboration between Hexcel and NASA over several years on the development of MDOF technology led to the successful test results on this latest flight test.

Clark Smith, director of Technology, Core Products at Hexcel says, “We have continued to improve the technology through taking advantage of the single cell treatment concept, by adding capability that the industry was looking for.”

The ability to attenuate a broader noise frequency range and increase acoustic absorption with the Hexcel liner has allowed an optimized design of the overall inlet that reduces drag and improves noise attenuation. 

 

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Hexcel will also be presenting at Carbon Fiber 2018. Learn more about the event at carbonfiberevent.com.