Lagrangian simulation of transverse jets with a distribution-based diffusion scheme

Transverse jets form a dominant group of flow fields arising in many applications of modern energy utilization, including propulsion and effluent dispersion. Furthermore, they form canonical examples where the flow field is dominated by large-scale and small-scale vortical structures, whose inter-related dynamics is a challenging subject in modern fluid mechanics. This study seeks a mechanistic understanding of the vortical structures of the transverse jet and their evolution. A set of massively parallel three-dimensional vortex simulations of high-momentum transverse jets at intermediate Reynolds number, utilizing a discrete filament representation of the vorticity field to capture stretching and tilting of vorticity, is performed. A diffusion scheme to treat viscosity at intermediate Reynolds number is formulated and analyzed in a distribution-based description. The implementation of the diffusion scheme is achieved by performing interpolation, which is a process that has been widely used to regularize particle distributions in vortex simulations, with a new set of interpolation kernels. These kernels provide an accurate and efficient way to simulate vorticity diffusion in transverse jets. An improved formulation of the vorticity flux boundary conditions is rigorously derived.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Wee, Daehyun, 1974-

Advisor dc:contributor.advisor

• Ahmed F. Ghoniem.

• Mechanical Engineering.

Statement dc:rights

• 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.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/40290

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/40290