Whether you're a tired passenger on a cross-country flight or an engineer designing a next-generation aircraft, you likely have an appreciation for noise reduction.
Airframe noise is mainly caused by the airflow around an aircraft’s landing gear, specifically the high-lift devices such as wing flaps and slats. During landing, as the plane reduces power, the airframe and landing gear can end up making as much racket as the engine.
Increasingly, commercial aircraft manufacturers face requirements to reduce the “community noise” produced by their aircraft's engine and airframe.
The above aircraft visualization, our Image of the Week, demonstrates the air flow field surrounding a Boeing 777's landing gear. The simulation runs on NASA's supercomputers, located in Ames Research Center. The imagery allows researchers to better understand and predict the flow-behavior changes that contribute to airframe noise.
The NASA/Boeing simulation represents the complex unsteady flow generated by the gear components. The visualization’s green color denotes slower velocities, while the red color indicates an increase in speed. A strong vortex (red!) appears coming off the edge of the landing gear doors.
The image was one of 35 computational achievements that NASA showcased this week at SC17, the international supercomputing conference in Denver, Colorado.
Many of our Tech Briefs review ways that engineers can cut down on the noise. Find a quiet place and read the articles below:
- NASA's new system of nozzles redistributes jet exhaust. The technology reduces noise in aircraft that have engines mounted above the wing, tail, or fuselage.
- A new program, ANOPP2, accurately predicts noise from both current and future concept aircraft and propulsion systems.
- Have a look at Langley Research Center's acoustic aircraft liners.
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