本研究主要目的在利用直接模擬蒙地卡羅法(DSMC)，對三維超音速衝壓引擎之內流場與燃料混合效率進行模擬，探討在不同馬赫數及外型下進氣道內部流場之變化，研究結果可觀察到斜震波及正震波的產生，將影響燃燒室氫氣之混合品質。模擬入口流條件為12、15、18馬赫，而外型區分為凹槽與凹槽後方斜率兩種，本研究希望藉由三維之模擬，進而與二維做比較增加準確性，作為爾後主要模擬之有利工具。 In this study, the direct simulation Monte Carlo method was used in simulating the internal flow field and fuel mixing efficiency of a three-dimensional supersonic combustion ramjet (scramjet) engine to investigate the changes in the internal field of air inlets at varying Mach numbers and for different physical appearances. The study results show that oblique shock waves and normal shock waves affect the mixing quality of hydrogen in the combustion chamber. The simulated air inlet conditions were 12, 15, and 18 Mach. In addition, two types of physical appearances were tested, specifically, concave cavity and rear-ramped concave cavity. By comparing the results obtained from the three-dimensional simulations with extant two-dimensional simulation results, this study endeavors to increase simulation accuracy. These comparative results can then be used as a reference for conducting major simulations in the future.
