The Advanced Noise Control Fan Baseline Measurements

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

doi:10.2514/6.2009-624

Cited by 23 publications

(14 citation statements)

References 2 publications

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“…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%

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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)

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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

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Section: Available Far Field Acoustic Measurementsmentioning

confidence: 99%

“…Results in this area are sensitive to the geometry and missing details or parts can explain the discrepancy. A complete description of the ANCF facility is available in publications 14,15 for comparison. The absence of tip clearance and outlet shaft are also good candidates to explain the differences.…”

Section: B Far-field Sound Pressure Levelsmentioning

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)

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“…For details of how the data were acquired and processed see reference 10. Keep in mind that the liners were not individually designed for optimum attenuation, but rather to validate the design and manufacture process.…”

Section: Resultsmentioning

confidence: 99%

In-Duct and Farfield Experimental Measurements from the ANCF for the Purpose of Improved Broadband Liner Optimization

Sutliff

Jones

Nark

2014

20th AIAA/CEAS Aeroacoustics Conference

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A process for the design and evaluation of novel broadband acoustic liner concepts with limited fan source information is being evaluated. A pair of advanced broad-bandwidth liners were designed and manufactured for the NASA Glenn Research Center's Advanced Noise Control Fan (ANCF): (i) a constant impedance liner and (ii) a variable impedance liner. The insertion loss of both liners was measured in-duct utilizing the ANCF's Configurable Fan Artificial Noise System in a clean configuration with no-flow. Additionally, the acoustic characteristics of the VariableImpedance Liner were measured in the standard ANCF configuration with and without flow. The experimental setup, in-duct mode power levels, and far-field directivity are presented herein.

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“…Figure 5 shows the far-field directivity of the generated mode at AE modes and M ¼ 0 or À0.12. Far-field acoustic directivities 14 were acquired using 30 microphones placed at a 12 ft radius from the duct centerline and 10 ft high. Fifteen of these were in an arc about the inlet exit plane (0 -90 measured from the inlet axis) and 15 were in an arc about the exhaust exit plane (90 -165 with 180 being the exhaust axis).…”

Section: Horizontal Orientationmentioning

confidence: 99%

Artificial noise systems for parametric studies of turbo-machinery aero-acoustics

Sutliff

Walker

2016

International Journal of Aeroacoustics

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The study of turbo-machinery aero-acoustics encompasses source generation, duct propagation, and radiation to the far field for the purposes of physical understanding, evaluation, and noise reduction. Further, the acoustics subset can be divided into overall, broadband, or tone emphasis. Ultimately, assessments on full-scale turbofans are required. However, for isolating specific effects, or for costs reasons, it is useful to test models. These models may be scaled versions of turbofan components depending on the physical process of interest. The advantage of using models is the lower cost allows for a wider range of conditions to be studied. Even so, the cost of manufacturing and testing scale model fans in mid-technology readiness level can be limiting. A potentially useful supplement to turbo-machinery aero-acoustics studies is the use of artificial sources to generate acoustic signatures. The advantage is that a wide range of signatures can be quickly and efficiently studied, particularly useful for noise reduction concepts, or validating prediction methodologies that are sensitive to variations in geometry or acoustic signature. A disadvantage is the lack of the ability to study source generation. This trade-off must be considered carefully when deciding on the usefulness of utilizing fan artificial noise sources for the study of turbo-machinery aero-acoustics. This paper presents two test articles that have contributed to turbo-machinery aero-acoustics studies. One is a 48 in. diameter duct (nominally full-scale) generating acoustic signatures in the audible range; the second is a 6 in. diameter duct (nominally scaled) generating acoustic signatures in the ultrasonic range.

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The Advanced Noise Control Fan Baseline Measurements

Cited by 23 publications

References 2 publications

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

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

In-Duct and Farfield Experimental Measurements from the ANCF for the Purpose of Improved Broadband Liner Optimization

Artificial noise systems for parametric studies of turbo-machinery aero-acoustics

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