The Advanced Noise Control Fan

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

doi:10.2514/6.2006-3150

Cited by 34 publications

(25 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4. Equations (3)(4)(5) were then used to compute the corresponding characteristic impedance and propagation constant for this foam metal. These intrinsic acoustic properties were then used to predict the acoustic impedance spectrum for the 1.275-in.-thick sample.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Low-Speed Fan Noise Attenuation from a Foam-Metal Liner

Sutliff

Jones

2009

Journal of Aircraft

View full text Add to dashboard Cite

A foam-metal liner for attenuation of fan noise was developed for and tested on a low-speed fan. This type of liner represents a significant advance over traditional liners, due to the possibility of placement in close proximity to the rotor. An advantage of placing treatment in this region is that the acoustic near field is modified, thereby inhibiting the noise-generation mechanism. This can result in higher attenuation levels than could be achieved by liners located in the nacelle inlet. In addition, foam-metal liners could potentially replace the fan rub strip and containment components, ultimately reducing engine components and thus weight, which can result in a systematic increase in noise reduction and engine performance. Foam-metal liners have the potential to reduce fan noise by 4 dB based on this study.

show abstract

Section: Resultsmentioning

confidence: 99%

“…The test bed for the FML was the advanced noise-control fan [5] (ANCF), a 4-ft-diam low-speed fan used for validation of noisereduction concepts. The ANCF is a highly configurable, ducted fan rig located in the Aero-Acoustic Propulsion Laboratory [6] (AAPL) at the NASA John H. Glenn Research Center at Lewis Field.…”

Section: Low-speed-fan Testingmentioning

confidence: 99%

Low-Speed Fan Noise Attenuation from a Foam-Metal Liner

Sutliff

Jones

2009

Journal of Aircraft

View full text Add to dashboard Cite

show abstract

“…Tones Power Levels (PWL) are computed from the measured Sound Pressure Level (SPL) at the BPFs up to the 6 th fan harmonics for each microphone. Other dynamic and static pressure probes are also available in the measurements 14,15 . More recent measurements 14 include flow characterizations using hot-film anemometer as well as dedicated aerodynamic performance measurements 16 including further static and total pressure probe rakes allowing mass flow as well as shaft axial velocities measurements.…”

Section: Available Far Field Acoustic Measurementsmentioning

confidence: 99%

Advanced Noise Control Fan Direct Aeroacoustics Predictions Using a Lattice-Boltzmann Method

Mann¹,

Pérot²,

Kim³

et al. 2012

18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference)

View full text Add to dashboard Cite

A Lattice-Boltzmann Method (LBM) based approach is used to perform transient, explicit and compressible CFD/CAA simulations on the Advanced Noise Control Fan (ANCF) configuration. The complete 3-D ducted rotor/stator model including all the geometrical details and the truly rotating rotor is simulated. Detailed near and far-field measurements conducted at the NASA Glenn research center are used to validate the simulation results. The measured and predicted sound pressure levels at the far-field microphones are compared and both show the presence of broadband noise and sharp peaks which frequencies depend on the number of rotor blades and the angular velocity of the rotor. The 3-D duct acoustics modes observed in experiments are also captured in the 3-D transient CFD/CAA calculation and detailed analyses of the results are presented. The main circumferential modes predicted from the number of rotor blades and stator vanes are recovered in both experimental and simulation modal decompositions. Nomenclature M = Mach number f k = k -th BPF harmonic order c b = Rotor blade chord s b = Rotor blade span Δx tip = Tip clearance c v = Stator vane chord d h,up = Upstream hub diameter d h,do = Downstream hub diameter p = Static pressure r = Radial coordinate θ = Azimuthal coordinate x = Axis coordinate t = Time m = Circumferential mode order n = Radial mode order k = x-axis eigenvalue κ = radial eigenvalue J m = Bessel function of the first kind and order m B = Number of fan blades V = Number of stator vanes s = Fan shaft harmonic Ω = Rotation frequency of the fan c 0 2 R 0 = Fan radius ρ 0 = Air density C i = Discrete collision component in the i -th direction c i = Discrete velocity component in the i -th direction f i = Particle distribution function in the i -th direction T = Temperature τ = Relaxation time ν = Kinematic viscosity ∆t = Numerical time step

show abstract

“…Results from these tests were then used to select the most promising configurations for low-speed fan rig (LSFR) tests in the NASA Glenn Advanced Noise Control Fan, a 48-inch-diameter fan rig (operates at flow speeds up to about Mach 0.15). 4 Encouraging broadband noise reduction were achieved with the LSFR. However, further validation at more realistic flow speeds was needed.…”

Section: Introductionmentioning

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

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

The Advanced Noise Control Fan

Cited by 34 publications

References 9 publications

Low-Speed Fan Noise Attenuation from a Foam-Metal Liner

Low-Speed Fan Noise Attenuation from a Foam-Metal Liner

Advanced Noise Control Fan Direct Aeroacoustics Predictions Using a Lattice-Boltzmann Method

Assessment of Soft Vane and Metal Foam Engine Noise Reduction Concepts

Contact Info

Product

Resources

About