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dc.contributor.authorBanyassady, Rayhaneh
dc.contributor.otherQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))en
dc.date2015-05-11 16:36:25.557en
dc.date.accessioned2015-05-13T15:12:53Z
dc.date.available2015-05-13T15:12:53Z
dc.date.issued2015-05-13
dc.identifier.urihttp://hdl.handle.net/1974/13076
dc.descriptionThesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2015-05-11 16:36:25.557en
dc.description.abstractLarge-eddy simulations were carried out to investigate the flow dynamics of wall jets over smooth and rough surfaces. Results were validated against data in the literature. A sand-grain roughness model is used, based on an immersed boundary method. To understand the extent to which the outer/inner layer modifies the inner/outer layer and the extent to which the effect of roughness spreads away from the wall, instantaneous and mean flow fields were investigated. For the Reynolds numbers and roughness heights considered in this study, the effect of roughness is mostly confined to the near-wall region in both plane and radial configurations. There is no structural difference between the outer layer over smooth and rough surfaces. Roughness does not affect either the size of the outer-layer structures or the scaling of the profiles of Reynolds stresses in the outer layer. However, in the inner layer, roughness redistributes stresses from streamwise to wall-normal and spanwise directions. Contours of joint probability-density function of the streamwise and wall-normal velocity fluctuations at the bottom of the logarithmic region match those of the turbulent boundary layer at the same height; traces of the outer-layer structures were detected at the top of the logarithmic region, indicating that they do not affect the flow very close to the wall, but still modify a major portion of the inner layer. Simulations of plane and radial wall-jets at several Re numbers were then investigated to, first, compare the plane and radial wall-jets and, second, to quantify the interaction of inner and outer layers. In both cases, the local Reynolds number is an important determining factor in characterization of the flow. The joint probability density function analysis shows that the local Reynolds number determines the level of intrusion of the outer layer into the inner layer. As the local Reynolds number increases, the thickness of the overlap layer becomes smaller, and the inner layer of the wall jet becomes more similar to the conventional turbulent boundary layer, i.e., the extent of the logarithmic region of the wall jets increases and its slope gets closer to the universal law of the wall.en_US
dc.languageenen
dc.language.isoenen_US
dc.relation.ispartofseriesCanadian thesesen
dc.rightsQueen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canadaen
dc.rightsProQuest PhD and Master's Theses International Dissemination Agreementen
dc.rightsIntellectual Property Guidelines at Queen's Universityen
dc.rightsCopying and Preserving Your Thesisen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectplane wall-jeten_US
dc.subjectimmersed boundary methoden_US
dc.subjectlarge-eddy simulationen_US
dc.subjectinner/outer layer interactionen_US
dc.subjectroughnessen_US
dc.subjectradial wall-jeten_US
dc.subjectlogarithmic law of the wallen_US
dc.titleLarge-Eddy Simulations of Plane and Radial Wall-Jets over Smooth and Rough Surfacesen_US
dc.typeThesisen_US
dc.description.degreePh.Den
dc.contributor.supervisorPiomelli, Ugoen
dc.contributor.departmentMechanical and Materials Engineeringen


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