FJ44 Turbofan Engine Test at NASA Glenn Research Center's Aero-Acoustic Propulsion Laboratory

Lauer, Joel T.; McAllister, Joseph; Loew, Raymond A.; Sutliff, Daniel L.; Harley, Thomas C.

doi:10.2514/6.2009-620

Cited by 5 publications

(3 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The third, conducted with a stainless steel OTR metal foam liner in a Williams International FJ44-3A engine (20-inch-diameter fan used for business jets), demonstrated significant broadband noise reduction at up to transonic fan tip speeds, with corresponding flow speeds through the inlet up to just less than Mach 0.6. 10,11 These results clearly demonstrate that OTR metal foam liners offer significant noise reduction potential, but further investigation is needed to optimize their implementation.…”

Section: Introductionmentioning

confidence: 83%

See 1 more Smart Citation

Assessment of Soft Vane and Metal Foam Engine Noise Reduction Concepts

Jones

Parrott

Sutliff

et al. 2009

15th AIAA/CEAS Aeroacoustics Conference (30th AIAA Aeroacoustics Conference)

Self Cite

View full text Add to dashboard Cite

Two innovative fan-noise reduction concepts developed by NASA are presented -soft vanes and over-the-rotor metal foam liners. Design methodologies are described for each concept. Soft vanes are outlet guide vanes with internal, resonant chambers that communicate with the exterior aeroacoustic environment via a porous surface. They provide acoustic absorption via viscous losses generated by interaction of unsteady flows with the internal solid structure. Over-the-rotor metal foam liners installed at or near the fan rotor axial plane provide rotor noise absorption. Both concepts also provide pressure-release surfaces that potentially inhibit noise generation. Several configurations for both concepts are evaluated with a normal incidence tube, and the results are used to guide designs for implementation in two NASA fan rigs. For soft vanes, approximately 1 to 2 dB of broadband inlet and aft-radiated fan noise reduction is achieved. For over-the-rotor metal foam liners, up to 3 dB of fan noise reduction is measured in the low-speed fan rig, but minimal reduction is measured in the high-speed fan rig. These metal foam liner results are compared with a static engine test, in which inlet sound power level reductions up to 5 dB were measured. Brief plans for further development are also provided.

show abstract

Section: Introductionmentioning

confidence: 83%

“…Multiple FeCrAlY samples were tested with the NIT and the Two-Thickness Method (Eqs. [10][11][12][13][14] As mentioned earlier, the frequency range of interest for noise reduction with the HSFR was approximately 1600 to 5300 Hz. Clearly, the results in Fig.…”

Section: Foam Evaluationmentioning

confidence: 99%

Assessment of Soft Vane and Metal Foam Engine Noise Reduction Concepts

Jones

Parrott

Sutliff

et al. 2009

15th AIAA/CEAS Aeroacoustics Conference (30th AIAA Aeroacoustics Conference)

Self Cite

View full text Add to dashboard Cite

show abstract

“…Therefore, aircraft and engine manufacturers are facing increasing pressure to reduce exterior noise levels. The use of large fans and inlet ducts means that fan noise is nowadays one of the principal sources of engine noise (Hanson 2001;Astley et al 2011;Glegg, Jochault 1997;Lauer et al 2009). In this paper, an overview of major accomplishments from recent research on fan noise reduction will be presented.…”

Section: Introductionmentioning

confidence: 99%

Main Fan Noise Mitigation Technologies in Turbofan Engines

Ommi

Azimi

2014

Aviation

View full text Add to dashboard Cite

abstract. Aircraft noise and emissions have been of concern since the beginning of commercial aviation. The continuing growth in air traffic and increasing public awareness have made environmental considerations one of the most critical aspects of commercial aviation today. To deal with this problem, aircraft manufacturers and public establishments are engaged in research on technical and theoretical approaches for noise reduction concepts that should be applied to new aircraft. While jet noise was the dominating contributor in the early jet engine designs, the noise emitted by the fan has become important with the reduction in jet speed and its control requiring an immense research effort. This paper concerns the main fan noise mitigation technologies in turbofan engines.

show abstract