Aerated-liquid atomization, which is produced by the introduction of gas directly into a liquid flow immediately upstream of the injector exit orifice to generate a two-phase flow, has been shown to produce well-atomized sprays in a quiescent environment with only a small amount of aerating gas at relatively low injection pressures. A time-derivative preconditioning method using the Low-Diffusion Flux-Splitting Scheme (LDFSS) has been extended to a ?mixture? model of two-phase flow and applied to simulate the structure of internal two-phase flow for aerated-liquid injectors, with each phase governed by its own equation of state. The Continuum Surface Force (CSF) model of Brackbill, et al. is adapted to model compressible fluid flow influenced by interfacial surface tension. A sub-iterative time integration method based on a planar Gauss-Seidel partitioning of the system matrix is used with implicit source terms as a means of solving the three-dimensional, time-dependent form of the governing equations. The calculations are parallelized using domain-decomposition and Message-Passing Interface (MPI) methods, and are optimized for operation on the 720 processor IBM SP-2 at the North Carolina Supercomputing Center (NCSC). Simulation results for 2-D aerated-liquid injector flowfields at gas-to-liquid (GLR) mass ratios of 0.08% and 2.45% are discussed. In accord with experimental visualization data, the results for GLR = 0.08% indicate a combination of slugging and core-annular two-phase flow in the injector. Results at GLR = 2.45% indicate that a core-annular flow mode dominates, again in agreement with experimental results. The effects of the choice of reference velocity and the level of surface tension on the injector flowfield solutions are also examined.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-09162002-133800 |
| Date | 17 September 2002 |
| Creators | Tian, Ming |
| Contributors | Dr. Jack R. Edwards, Dr. Semyon V. Tsynkov, Dr. Hassan A. Hassan |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-09162002-133800/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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