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The Fan Acoustics Test & Evaluation (FATE) Bed is integrated into the ESI Open Jet Acoustics Test Section. This open jet wind tunnel inlet supplies external airflow through a 3’ x 3’ square nozzle at speeds currently up to 60 mph* and turbulence levels on the order of 0.5 %. (*Both increased speed and nozzle size are also available.)

FATE Bed was developed to:

  • Enable high quality sound measurements without the fear of background noise contamination.

  • Minimize wall reflections by providing a relatively large acoustically treated test section/quasi-anechoic chamber.  The chamber volume is 3700 ft3 and has dimensions of 12’ x 12’ x 26’.

  • FATE Bed offers both conventional and laser based diagnostics, as well as high speed flow visualization and imaging.

Test model fabrication is guided by ESI’s expertise in fluid dynamics, turbulence, and aeroacoustic’s. Potential models undergo a review process to determine if the integration of miniature surface mounted microphones can aid in the identification of potential noise sources.

Then using ESI’s in-house fabrication & rapid prototype capabilities, modified component drawings are generated and test components are fabricated using 3D printing (see adjacent blade array image).  

All Particle Image Velocimetry (PIV) flow field data is acquired and analyzed using proprietary ESI algorithms and correlated for accuracy.

PIV results of each test are examined and solutions offered to bring about reductions in the aero-acoustic sound pressure levels (SPL).

A LabView controlled high speed data acquisition system is utilized for all non-laser based measurements. This system allows for:

  • Acoustic and fan performance data to be simultaneously acquired at high speed.

  • Multiple channels to enable far field acoustic levels as well as localized surface  measurements.

Once a test unit is installed into FATE Bed a baseline acoustic profile is acquired. The right hand image is a typical acoustic profile acquired from the above printed stationary blade cascade. 

After the acoustic signatures of the blade cascade are examined, flow visualization is initiated and followed by local and full field fluid dynamic measurements, using techniques as Particle Image Velocimetry. 

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