Jets in crossflow are used in a wide range of engineering applications and have been
studied for more than 60 years. The transversal penetration and structure of a jet placed
in a crossflow is known to be strongly three-dimensional. It is believed that, by using a
pulsed jet inclined in the crossflow direction, the momentum transport can be controlled
in two very efficient ways: the pulse can increase the jet penetration and the mixing
downstream, while the inclination avoids the creation of a reverse flow at the jet exit
and may extend the mixing area further downstream. Although some results are
available in the literature focusing on components of this problem, none addresses the
combination of these two factors. Moreover, most of these studies use elaborate flow
visualizations and 2-D velocity measurement methods that may not be adequate to
elucidate the complexity of such a flow.
This study addresses these issues by using stereoscopic PIV measurements for a
steady and fully modulated jet at a constant mean velocity ratio, V[subscript r], of 3.4. For the
steady jet case, the effect of the jet Reynolds number, Re[subscript j], is investigated. For the
pulsed case, the effect of a low pulsing frequency is considered as well as the pulse duty
cycle. For each case, the mean three-component velocity field is examined. Proper
Orthogonal Analysis (POD) of vorticity and turbulent kinetic energy are used to further
evaluate the vortical and turbulent characteristics of the jet. In addition, a vortex
detection algorithm, and 3D rendering of the flow streamlines are used to study the near
field vortical flow structure of the jet flow. / Graduation date: 2006
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28988 |
| Date | 29 November 2005 |
| Creators | Dano, Bertrand P. E. |
| Contributors | Liburdy, James A. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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