Show simple item record

dc.contributor.advisorGao, Xinfeng
dc.contributor.authorSpotts, Nathan
dc.contributor.committeememberGuzik, Stephen
dc.contributor.committeememberSakurai, Hiroshi
dc.contributor.committeememberAlves, Goldino
dc.contributor.committeememberLiu, Jiangguo
dc.date.accessioned2016-01-11T15:13:58Z
dc.date.available2016-01-11T15:13:58Z
dc.date.issued2015
dc.descriptionIncludes bibliographical references.
dc.description2015 Fall.
dc.description.abstractAs modern trends in commercial aircraft design move toward high-bypass-ratio fan systems of increasing diameter with shorter, nonaxisymmetric nacelle geometries, inlet distortion is becoming common in all operating regimes. The distortion may induce aerodynamic instabilities within the fan system, leading to catastrophic damage to fan blades, should the surge margin be exceeded. Even in the absence of system instability, the heterogeneity of the flow affects aerodynamic performance significantly. Therefore, an understanding of fan-distortion interaction is critical to aircraft engine system design. This thesis research elucidates the complex fluid dynamics and fan-distortion interaction by means of computational fluid dynamics (CFD) modeling of a complete engine fan system; including rotor, stator, spinner, nacelle and nozzle; under conditions typical of those encountered by commercial aircraft. The CFD simulations, based on a Reynolds-averaged Navier-Stokes (RANS) approach, were unsteady, three-dimensional, and of a full-annulus geometry. A thorough, systematic validation has been performed for configurations from a single passage of a rotor to a full-annulus system by comparing the predicted flow characteristics and aerodynamic performance to those found in literature. The original contributions of this research include the integration of a complete engine fan system, based on the NASA rotor 67 transonic stage and representative of the propulsion systems in commercial aircraft, and a benchmark case for unsteady RANS simulations of distorted flow in such a geometry under realistic operating conditions. This study is unique in that the complex flow dynamics, resulting from fan-distortion interaction, were illustrated in a practical geometry under realistic operating conditions. For example, the compressive stage is shown to influence upstream static pressure distributions and thus suppress separation of flow on the nacelle. Knowledge of such flow physics is valuable for engine system design.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.identifierSpotts_colostate_0053N_13363.pdf
dc.identifier.urihttp://hdl.handle.net/10217/170387
dc.languageEnglish
dc.publisherColorado State University. Libraries
dc.relation.ispartof2000-2019 - CSU Theses and Dissertations
dc.rightsCopyright of the original work is retained by the author.
dc.subjectCFD
dc.subjectinlet distortion
dc.subjectrotor 67
dc.titleUnsteady Reynolds-averaged Navier-Stokes simulations of inlet flow distortion in the fan system of a gas-turbine aero-engine
dc.typeText
dcterms.rights.dplaThe copyright and related rights status of this item has not been evaluated (https://rightsstatements.org/vocab/CNE/1.0/). Please refer to the organization that has made the Item available for more information.
thesis.degree.disciplineMechanical Engineering
thesis.degree.grantorColorado State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (M.S.)


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record