Studies on the Dynamic Characteristics of Planar Thermal Jet Using a Lagrangian Approach
碩士 === 國立成功大學 === 機械工程學系碩博士班 === 97 === A Lagrangian approach involved the virtual temperature particles is presented in this study. In addition, the dynamic characteristics of two-dimensional planar thermal jet are simulated and investigated by this approach combining with the vortex method of rand...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2009
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| Online Access: | http://ndltd.ncl.edu.tw/handle/61730592824817084745 |
| Summary: | 碩士 === 國立成功大學 === 機械工程學系碩博士班 === 97 === A Lagrangian approach involved the virtual temperature particles is presented in this study. In addition, the dynamic characteristics of two-dimensional planar thermal jet are simulated and investigated by this approach combining with the vortex method of random walk. This research is fully separated into forced thermal jet without heat-flow coupling and starting thermal jet with heat-flow coupling as follows. In the first part of present study, the turbulent investigations on the spatial evolution characteristics of the forced thermal jet with different Reynolds numbers and Prandtl numbers are studied. The numerical results are not only reasonable but also get excellent agreement with the experimental data of available literatures. The clear interface and diffusive transportations of momentum and heat energy are observed. The agreeable self-similar relations with Gaussian distribution and consistent development with experimental data of the velocity and temperature half-widths are obtained as well. Besides, the decay properties of the velocity and temperature from the jet centerline are valid. In the second part of this study, the investigations on the development properties of the starting thermal jet with different Richardson numbers are studied. The numerical results show that the acceleration in flow field obviously as the Richardson numbers increase. It is also observed that the original vortex of flow field is driven by the generated vortex of thermal field.
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