Analytical Study of the Effects of Wind Tunnel Turbulence on Turbofan Rotor Noise

Analytical Study of the Effects of Wind Tunnel Turbulence on Turbofan Rotor Noise PDF Author:
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ISBN:
Category :
Languages : en
Pages : 132

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Analytical Study of the Effects of Wind Tunnel Turbulence on Turbofan Rotor Noise

Analytical Study of the Effects of Wind Tunnel Turbulence on Turbofan Rotor Noise PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 132

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Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 702

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The Shock and Vibration Digest

The Shock and Vibration Digest PDF Author:
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 660

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Ames Research Center Publications: A Continuing Bibliography, 1980

Ames Research Center Publications: A Continuing Bibliography, 1980 PDF Author:
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ISBN:
Category :
Languages : en
Pages : 268

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Noise Benefits of Rotor Trailing Edge Blowing for a Model Turbofan

Noise Benefits of Rotor Trailing Edge Blowing for a Model Turbofan PDF Author: National Aeronaut Administration (Nasa)
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ISBN:
Category :
Languages : en
Pages : 32

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An advanced model turbofan was tested in the NASA Glenn 9- by 15-Foot Low Speed Wind Tunnel (9x15 LSWT) to explore far field acoustic effects associated with rotor Trailing-Edge-Blowing (TEB) for a modern, 1.294 stage pressure ratio turbofan model. The TEB rotor (Fan9) was designed to be aerodynamically similar to the previously tested Fan1, and used the same stator and nacelle hardware. Fan9 was designed with trailing edge blowing slots using an external air supply directed through the rotor hub. The TEB flow was heated to approximate the average fan exit temperature at each fan test speed. Rotor root blockage inserts were used to block TEB to all but the outer 40 and 20% span in addition to full-span blowing. A configuration with full-span TEB on alternate rotor blades was also tested. Far field acoustic data were taken at takeoff/approach conditions at 0.10 tunnel Mach. Far-field acoustic results showed that full-span blowing near 2.0% of the total flow could reduce the overall sound power level by about 2 dB. This noise reduction was observed in both the rotor-stator interaction tones and for the spectral broadband noise levels. Blowing only the outer span region was not very effective for lowering noise, and actually increased the far field noise level in some instances. Full-span blowing of alternate blades at 1.0% of the overall flow rate (equivalent to full-span blowing of all blades at 2.0% flow) showed a more modest noise decrease relative to full-span blowing of all blades. Detailed hot film measurements of the TEB rotor wake at 2.0% flow showed that TEB was not every effective for filling in the wake defect at approach fan speed toward the tip region, but did result in overfilling the wake toward the hub. Downstream turbulence measurements supported this finding, and support the observed reduction in spectral broadband noise. Glenn Research Center NASA/TM-2007-214666, E-15802, AIAA Paper 2007-1241 TRAILING EDGES; ENGINE NOISE; AIRCRAFT ENGINES; AEROACOUSTICS; SPANWISE BLOWING; TURBOFAN ENGINES; LOW SPEED WIND TUNNELS; NOISE REDUCTION; FAR FIELDS; PRESSURE RATIO; BROADBAND; WAKES; DEFECTS

International Aerospace Abstracts

International Aerospace Abstracts PDF Author:
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ISBN:
Category : Aeronautics
Languages : en
Pages : 1048

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NASA Technical Memorandum

NASA Technical Memorandum PDF Author:
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ISBN:
Category : Aeronautics
Languages : en
Pages : 310

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NASA SP.

NASA SP. PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 580

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Government Reports Announcements & Index

Government Reports Announcements & Index PDF Author:
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ISBN:
Category : Science
Languages : en
Pages : 1402

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Broadband Rotor Noise Analyses

Broadband Rotor Noise Analyses PDF Author: Albert R. George
Publisher:
ISBN:
Category : Rotors
Languages : en
Pages : 104

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