A novel concept of multilayer micro structurally controlled noise mitigation porous material was developed and experimentally validated in the laboratory by normal incidence impedance test. Extensive parametric studies were made to understand various parameters that influence acoustic absorption and transmission loss based on the test specimen size, particle size, porosity, pore size, and its distribution through the thickness. The results were reported in many publications. This work was focused on applying the concept and assessing the validity of the technology to aircraft turbomachine engines. The NASA Glenn Research Center’s Advanced Noise Control Fan (ANCF) low-speed test rig was selected. The liner insert required a 4-ft internal diameter cylinder with a 2-inch thick and 9-inch axial length. The liner was fabricated in eight segments and assembled in an aluminum test rig. The liner was tested for both tonal and broadband noise at the Notre Dame Turbomachinery Lab White Field test facility, where the ANCF is located. The study concludes that: Microstructurally controlled porous material is very effective in dissipating the sound energy; the liner is effective for tonal noise (2 to 13 dB reduction in noise levels) that constitutes the major part of the overall fan noise, especially the blade passing frequency which is generally the dominating component; Also, the liner is effective for broadband noise with reductions in sound pressure level of about 3 dB for the shaft order greater than 20. The proposed two-layer liner model demonstrated the validity of the concept. More studies are required to optimize the design.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Microstructure Controlled Multi-Layer Porous Material Liner Tested On The Advanced Noise Control Fan


    Contributors:

    Conference:

    2023 AIAA Aviation and Aeronautics Forum and Exposition (AIAA AVIATION Forum) ; 2023 ; San Diego, CA, US


    Type of media :

    Conference paper


    Type of material :

    No indication


    Language :

    English




    Microstructure Controlled Multi-Layer Porous Material Liner Tested On The Advanced Noise Control Fan

    Kenchappa, Bharath / Shivakumar, Kunigal / Sutliff, Daniel L. | AIAA | 2023


    Improved Broadband Liner Optimization Applied to the Advanced Noise Control Fan

    Nark, Douglas M. / Jones, Michael G. / Sutliff, Daniel L. | AIAA | 2014


    POROUS LINER SHEET

    OMORI TAIRA / TAKANO TOMOKO / TAKEDA HIROTAKA | European Patent Office | 2017

    Free access