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Broadband blade self noise prediction for subsonic prop fans
- Date Issued:
- 1996
- Summary:
- Broadband self-noise generated by rotating blades in a subsonic ducted propfan is studied for a hard walled cylindrical duct in a uniform flow. An expression for the induct sound power radiated by three self-noise mechanisms is derived: the Turbulent-Boundary-Layer-Trailing-Edge noise, the Laminar-Boundary-Layer-Vortex-Shedding noise and the Trailing-Edge-Bluntness noise. The present theory uses NASA's self-noise prediction methodology for an isolated airfoil. An efficient method of programming is presented which reduces the time of computation for multiple radial modes. The results obtained are presented, discussed and compared with Blade-Tip-Boundary-Layer fan noise predictions obtained using the SDPF code developed at FAU. The most important parameters which affect self-noise are found to be the angle of attack, the effective Mach number and the chord length of the blade. For high angles of attack, the TBL-TE noise gives significant amount of sound power especially at the low frequencies. For low effective Mach numbers and at certain angles of attack, the LBL-VS noise can have high power levels in the mid and high frequencies. Trailing edge bluntness noise appeared to give insignificant amounts of energy over the whole spectrum compared to the other self-noise mechanisms.
Title: | Broadband blade self noise prediction for subsonic prop fans. |
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Name(s): |
Jochault, Cyrille Andre. Florida Atlantic University, Degree grantor Glegg, Stewart A. L., Thesis advisor |
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Type of Resource: | text | |
Genre: | Electronic Thesis Or Dissertation | |
Issuance: | monographic | |
Date Issued: | 1996 | |
Publisher: | Florida Atlantic University | |
Place of Publication: | Boca Raton, Fla. | |
Physical Form: | application/pdf | |
Extent: | 137 p. | |
Language(s): | English | |
Summary: | Broadband self-noise generated by rotating blades in a subsonic ducted propfan is studied for a hard walled cylindrical duct in a uniform flow. An expression for the induct sound power radiated by three self-noise mechanisms is derived: the Turbulent-Boundary-Layer-Trailing-Edge noise, the Laminar-Boundary-Layer-Vortex-Shedding noise and the Trailing-Edge-Bluntness noise. The present theory uses NASA's self-noise prediction methodology for an isolated airfoil. An efficient method of programming is presented which reduces the time of computation for multiple radial modes. The results obtained are presented, discussed and compared with Blade-Tip-Boundary-Layer fan noise predictions obtained using the SDPF code developed at FAU. The most important parameters which affect self-noise are found to be the angle of attack, the effective Mach number and the chord length of the blade. For high angles of attack, the TBL-TE noise gives significant amount of sound power especially at the low frequencies. For low effective Mach numbers and at certain angles of attack, the LBL-VS noise can have high power levels in the mid and high frequencies. Trailing edge bluntness noise appeared to give insignificant amounts of energy over the whole spectrum compared to the other self-noise mechanisms. | |
Identifier: | 15255 (digitool), FADT15255 (IID), fau:12026 (fedora) | |
Collection: | FAU Electronic Theses and Dissertations Collection | |
Note(s): |
College of Engineering and Computer Science Thesis (M.S.E.)--Florida Atlantic University, 1996. |
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Subject(s): |
Blades--Noise Rotors--Noise Noise control Aerofoils--Noise |
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Held by: | Florida Atlantic University Libraries | |
Persistent Link to This Record: | http://purl.flvc.org/fcla/dt/15255 | |
Sublocation: | Digital Library | |
Use and Reproduction: | Copyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder. | |
Use and Reproduction: | http://rightsstatements.org/vocab/InC/1.0/ | |
Host Institution: | FAU | |
Is Part of Series: | Florida Atlantic University Digital Library Collections. |