Acoustic Benefits Of Stator Sweep And Lean For A High Tip Speed Fan PDF Download
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Author | : National Aeronautics and Space Administration (NASA) |
Publisher | : Createspace Independent Publishing Platform |
Total Pages | : 40 |
Release | : 2018-06-19 |
Genre | : |
ISBN | : 9781721295630 |
Download Acoustic Benefits of Stator Sweep and Lean for a High Tip Speed Fan Book in PDF, ePub and Kindle
A model high-speed fan stage was acoustically tested in the NASA Glenn 9- by 15-Foot Low Speed Wind Tunnel at takeoff/approach flight conditions. The fan was designed for a corrected rotor tip speed of 442 m/s (1450 ft/s), and had a powered core, or booster stage, giving the model a nominal bypass ratio of 5. The model also had a simulated engine pylon and nozzle bifurcation contained within the bypass duct. The fan was tested with three stator sets to evaluate acoustic benefits associated with a swept and leaned stator and with a swept integral vane/frame stator which incorporated some of the swept and leaned features as well as eliminated some of the downstream support structure. The baseline fan with the wide chord rotor and baseline stator approximated a current GEAE CF6 engine. A flyover effective perceived noise level (EPNL) code was used to generate relative EPNL values for the various configurations. Flyover effective perceived noise levels (EPNL) were computed from the model data to help project noise benefits. A tone removal study was also performed. The swept and leaned stator showed a 3 EPNdB reduction at lower fan speeds relative to the baseline stator; while the swept integral vane/frame stator showed lowest noise levels at intermediate fan speeds. Removal of the bypass blade passage frequency rotor tone (BPF) showed a 4 EPNdB reduction for the baseline and swept and leaned stators, and a 6 EPNdB reduction for the swept integral vane/ frame stator. Therefore, selective tone removal techniques such as active noise control and/or tuned liner could be particularly effective in reducing noise levels for certain fan speeds. Woodward, Richard P. and Gazzaniga, John A. and Bartos, Linda J. and Hughes, Christopher E. Glenn Research Center NASA/TM-2002-211345, E-13143, NAS 1.15:211345, AIAA Paper 2002-1034
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Total Pages | : 26 |
Release | : 2002 |
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Download Acoustic Benefits of Stator Sweep and Lean for a High Tip Speed Fan Book in PDF, ePub and Kindle
Author | : Gerhard Müller |
Publisher | : Springer Science & Business Media |
Total Pages | : 704 |
Release | : 2012-11-06 |
Genre | : Science |
ISBN | : 3540694609 |
Download Handbook of Engineering Acoustics Book in PDF, ePub and Kindle
This acoustics handbook for mechanical and architectural applications is a translation of the German standard work on the subject. It not only describes the state of art of engineering acoustics but also gives practical help to engineers for solving acoustic problems. It deals with the origin, the transmission and the methods of abatement of air-borne and structure-borne sound of different kinds, from traffic to machinery and flow induced sound.
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Total Pages | : 34 |
Release | : 2002 |
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Download Fan Noise Source Diagnostic Test: Far-Field Acoustic Results Book in PDF, ePub and Kindle
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Total Pages | : 638 |
Release | : 2002 |
Genre | : Aeronautics |
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Download 40th AIAA Aerospace Sciences Meeting & Exhibit Book in PDF, ePub and Kindle
Author | : Edmane Envia |
Publisher | : |
Total Pages | : 18 |
Release | : 2001 |
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Download Fan Noise Reduction: An Overview Book in PDF, ePub and Kindle
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Total Pages | : 246 |
Release | : 2003 |
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Download Design and Test of Fan/Nacelle Models Quiet High-Speed Fan Design Book in PDF, ePub and Kindle
Author | : |
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Total Pages | : 606 |
Release | : 2003 |
Genre | : Aeronautics |
ISBN | : |
Download 41st AIAA Aerospace Sciences Meeting & Exhibit Book in PDF, ePub and Kindle
Author | : |
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Total Pages | : 562 |
Release | : 2001 |
Genre | : Aeronautics |
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Download Aerospace America Book in PDF, ePub and Kindle
Author | : National Aeronautics and Space Administration (NASA) |
Publisher | : Createspace Independent Publishing Platform |
Total Pages | : 38 |
Release | : 2018-08-16 |
Genre | : |
ISBN | : 9781725641679 |
Download Design Selection and Analysis of a Swept and Leaned Stator Concept Book in PDF, ePub and Kindle
This report describes a theoretical design and analysis study of the benefits of vane sweep and lean for reducing rotor- stator interaction tone noise. It is shown that the kinematic relationship between the rotor wakes and stator vanes is the principal factor in determining the achievable noise reductions. Vane sweep and lean control rotor wake skewing as seen by the stator vanes and hence influence the number of wake intersections per vane. An increase in the number of intersections reduces noise levels. Hence, to reduce rotor-stator noise, van sweep and lean must be chosen in such a way as to increase wake intersections per vane. A simple design rule is thus proposed which requires a sweep configuration that puts the vane tip downstream of its root and a vane lean that is in the direction of the rotor rotation. A detailed comparison of the predicted and measured noise reductions for a swept and leaned stator is then carried out. Overall, these comparisons show that the predicted benefits of a swept and leaned stator are in good agreement, qualitative as well as quantitative, with the measured reductions for the fan speeds relevant to noise certification procedure. Furthermore, the results also demonstrate the validity of design criterion and the theoretical tools used in this study. Envia, Edmane and Nallasamy, M. Glenn Research Center NASA/TM-1998-208662, NAS 1.15:208662, E-11383 RTOP 538-03-11...