| Summary: | 博士 === 國防大學理工學院 === 國防科學研究所 === 101 === In present study, the major concern is the influence and application of gas particles and solid surface interaction models on rarefied gas simulation. Interaction of molecules and solid influences momentum flux, energy exchange, and flow motion in flow field. In this thesis, the direct simulation Monte Carlo method, which based on statistical mechanism and molecular model, is adopted as a computation tool. The effect of gas surface interaction model on rarefied gas natural convection in rectangular enclosure (Rayleigh-Bénard problem) and hypersonic rarefied gas through solid surface are investigated.
For Rayleigh-Bénard problem, different gas-surface interaction molels were applied to side-wall boundaries in three-dimensional rectangular enclosure. The variations of flow modes, heat flux, and influence of simulation conditions in rarefied gas flow field are studied. The validation demonstrated that present study agrees well in qualitative and quantitative analyses with the published results of the Stefanov's group. Besides, the discussion for the influence of different combinations of gas-surface interaction model is performed systematically on the three-dimensional natural convection flow field in rectangular enclosure.
In the problem of hypersonic rarefied gas flow over solid surface, the influence of gas-surface interaction model as high velocity flow over wedged body and shallow cavity is discussed. The computation results of flow over wedge body agree well with theoretical ones. The influence of momentum accommodation coefficient of gas-surface interaction model on pressure and temperature distribution is examined.
In present study, gas-surface interaction models are investigated in detail for further understanding of complex physics mechanisms. The results are expected to provide useful information for design and improvement of micro convection and high speed vehicle systems.
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