MIT Libraries homeMIT Libraries logoDSpace@MIT

MIT
View Item 
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Doctoral Theses
  • View Item
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Doctoral Theses
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Ultra-short nacelles for low fan pressure ratio propulsors

Author(s)
Peters, Andreas, Ph. D. Massachusetts Institute of Technology
Thumbnail
DownloadFull printable version (58.16Mb)
Other Contributors
Massachusetts Institute of Technology. Department of Aeronautics and Astronautics.
Advisor
Zoltán S. Spakovszky.
Terms of use
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582
Metadata
Show full item record
Abstract
This thesis addresses the uncharted inlet and nacelle design space for low pressure ratio fans for advanced aeroengines. A key feature in low fan pressure ratio (FPR) propulsors with short inlets and nacelles is the increased coupling between fan and inlet. The thesis presents an integrated fan-nacelle design framework, combining a spline-based tool for the denition of inlet and nacelle surfaces with a fast and reliable body-force-based approach for the fan rotor and stator blade rows. The new capability captures the inlet-fan and fan-exhaust interactions and the ow distortion at the fan face and enables the parametric exploration of the short-inlet design territory. The interaction of the rotor with a region of high streamwise Mach number at the fan face is identied as the key aerodynamic mechanism limiting the design of short inlets. The local increase in streamwise Mach number is due to ow acceleration along the inlet internal surface coupled with a reduction in eective ow area. For a candidate short-inlet design with inlet length to fan diameter ratio L=D = 0:19, the streamwise Mach number at the fan face near the shroud increases by up to 0:16 at cruise and by up to 0:36 at o-design conditions relative to a long-inlet baseline propulsor with L=D = 0:5. As a consequence, the rotor locally operates close to choke, resulting in fan eciency penalties of up to 1:6% at cruise and 3:9% at o-design. For inlets with L=D < 0:25, the benet from reduced nacelle drag is offset by the reduction in fan eciency, resulting in propulsive eciency penalties. Based on a parametric inlet study, the recommended inlet L=D for engine propulsive eciency benefits is suggested to be between 0:25 and 0:4. A candidate design with L=D = 0:25 maintains the cruise propulsive efficiency of the baseline case without jeopardizing fan and LPC stability at o-design conditions. On the aircraft system level, fuel burn benefits are conjectured to be feasible due to the reductions in nacelle weight and drag compared to an aircraft powered by the long-inlet baseline propulsor.
Description
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2014.
 
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
 
Cataloged from student-submitted PDF version of thesis.
 
Includes bibliographical references (pages 205-216).
 
Date issued
2014
URI
http://hdl.handle.net/1721.1/87128
Department
Massachusetts Institute of Technology. Department of Aeronautics and Astronautics
Publisher
Massachusetts Institute of Technology
Keywords
Aeronautics and Astronautics.

Collections
  • Doctoral Theses

Browse

All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

Login

Statistics

OA StatisticsStatistics by CountryStatistics by Department
MIT Libraries homeMIT Libraries logo

Find us on

Twitter Facebook Instagram YouTube RSS

MIT Libraries navigation

SearchHours & locationsBorrow & requestResearch supportAbout us
PrivacyPermissionsAccessibility
MIT
Massachusetts Institute of Technology
Content created by the MIT Libraries, CC BY-NC unless otherwise noted. Notify us about copyright concerns.