Show simple item record

dc.contributor.supervisor Wang, BingChen (Mechanical Engineering) en_US
dc.contributor.author Yan, Jiaxin
dc.date.accessioned 2018-09-11T15:08:54Z
dc.date.available 2018-09-11T15:08:54Z
dc.date.issued 2018-08 en_US
dc.date.submitted 2018-08-27T21:34:05Z en
dc.date.submitted 2018-09-11T02:03:42Z en
dc.identifier.uri http://hdl.handle.net/1993/33297
dc.description.abstract Direct numerical simulations are performed to investigate turbulent flows in a rectangular duct of aspect ratio varying from 1.0 to 3.0 at a fixed low Reynolds number 150. Persistent secondary flows of Prandtl’s second kind are observed in the corners of the ducts. As the aspect ratio increases, streamwise vortices near the top and bottom walls extend towards to the central vertical plane of ducts. Particularly, the displacement of vortex cores near the top/bottom wall can be described as a function of the distance to the sidewall. Detailed analyses of turbulence statistics including the mean flow, turbulent kinetic energy, turbulent intensities, Reynolds stress budgets, and pre-multiplied one-dimensional energy spectrum are conducted to understand the aspect ratio effects on the flow physics. In the duct of aspect ratio 3.0, hairpin flow structures are present in the central regions of the duct, and their characteristics are similar to those exhibited in the plane channel flows. Furthermore, as indicated by the energy spectra, a spanwise quasi-homogeneous region spans over approximately 270 wall units in the central region of the rectangular duct. en_US
dc.subject Direct numerical simulation, Turbulent flow, Rectangular duct, Coherent structures en_US
dc.title Direct numerical simulation of turbulent flows in a rectangular duct of different aspect ratios en_US
dc.degree.discipline Mechanical Engineering en_US
dc.contributor.examiningcommittee Kuhn, David (Mechanical Engineering) Maghoul, Pooneh (Civil Engineering) en_US
dc.degree.level Master of Science (M.Sc.) en_US
dc.description.note October 2018 en_US


Files in this item

This item appears in the following Collection(s)

Show simple item record

View Statistics