Experiments and direct numerical simulations (DNS) have been performed to
examine the e¤ects of initial conditions on the dynamics of a Rayleigh-Taylor unsta-
ble mixing layer. Experiments were performed on a water channel facility to measure
the interfacial and velocity perturbations initially present at the two-fluid interface
in a small Atwood number mixing layer. The experimental measurements have been
parameterized for use in numerical simulations of the experiment. Two- and three-
dimensional DNS of the experiment have been performed using the parameterized
initial conditions. It is shown that simulations implemented with initial velocity and
density perturbations, rather than density perturbations alone, are required to match
experimentally-measured statistics and spectra. Data acquired from both the exper-
iment and numerical simulations are used to examine the role of initial conditions on
the evolution of integral-scale, turbulence, and mixing statistics. Early-time turbu-
lence and mixing statistics are shown to be strongly-dependent upon the early-time
transition of the initial perturbation from a weakly-nonlinear to a strongly-nonlinear
flow.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/3130 |
| Date | 12 April 2006 |
| Creators | Mueschke, Nicholas Jay |
| Contributors | Andrews, Malcolm J. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 5236191 bytes, electronic, application/pdf, born digital |
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