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oai:www.ideals.illinois.edu:2142/84017 2023-07-11 col_2142_5131 col_2142_14787 com_2142_5130 com_2142_9630 com_2142_234

Dutton, J. Craig Lucht, Robert P. Meyer, Terrence Raymond 2015-09-25T21:13:10Z 2015-09-25T21:13:10Z 10000-01-01 2001 2001 The flow regimes studied in this investigation span three main stages of shear layer development. Vortex mixing in the near field of an axisymmetric jet (ReD = 2300) is studied by using an acoustic pulse to obtain repeatable vortex formation and merging events. Results indicate that the mixing process is initially slow within the laminar vortex rollers, but a dramatic increase in mixing is detected prior to and during vortex coalescence. In the next stage of research, non-pulsed axisymmetric jets from ReD = 16,200 to 29,200 were used to study the transition to small-scale turbulence. This transition was found to take place near the average location of vortex merging, and resulted in a 20 to 25% drop in the mixed jet fluid volume fraction, a 30 to 35% drop in the preferred mixed jet fluid fraction, and a shift from stationary to hybrid radial probability density functions. In the final stage of research, fully-developed turbulence was studied in the far-field region of a planar shear layer with low- to high-speed velocity ratios of 0.25 to 0.44. Statistical analysis in this regime indicated that the physics of molecular mixing differs between the lowand high-speed fluids, and that molecularly mixed fluid quantities are not uniform across the shear layer. Made available in DSpace on 2015-09-25T21:13:10Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9996663.pdf: 7854903 bytes, checksum: 14504e1e5a22313d572e1986cb5e0bba (MD5) Previous issue date: 2001 Embargo set by: Seth Robbins for item 85298 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 181 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2001. http://hdl.handle.net/2142/84017 (MiAaPQ)AAI9996663 eng Chemistry, Analytical Turbulent Molecular Mixing in Gaseous Free Shear Flows text Mechanical Engineering Mechanical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.