From current study the flow states of hypersonic inlet are classified into two types: start and unstart. Between start and unstart exists the double solution region, which forms the classical double solution theory of air inlet. However, because the shock in hypersonic inlet strongly interferes and interconnects with the boundary layer, it is very hard for the classical double solution theory to explain all flow phenomena. Profound study was done to improve understanding of hypersonic inlet and 4 distinct types of flow mode which disrelated with overrating were discovered from experiments, supplemented with CFD calculations. They are flow mode of start, large separation on body (LSB), small separation on body (SSB), and dual-separation on both body and lip (DSBL). The study also found that there is hysteresis phenomenon between the four types of flow mode and that their pairwise combinations produce six types of double solution region. Furthermore, according to the historical status and different entry paths, the study found out three types of triple solution region: “start + LSB + DSBL”, “LSB + SSB + DSBL”, and “start + SSB + DSBL”. The study results not only greatly enrich the theory of hypersonic inlet, but also have great significance in guiding engineering practice of air inlet.

从目前的研究来看，高超声速入口的流动状态分为两种类型：启动和未启动。start和unstart之间存在双解区域，形成了经典的进气道双解理论。然而，由于高超声速入口处的激波与边界层有强烈的干扰和相互联系，经典的双解理论很难解释所有的流动现象。进行了深入研究以提高对高超音速入口的理解，并从实验中发现了 4 种与高估无关的不同类型的流动模式，并辅以 CFD 计算。它们是启动流模式、体上大分离 (LSB)、体上小分离 (SSB) 和体唇双分离 (DSBL)。研究还发现，四种流动模式之间存在滞后现象，它们成对组合产生六种双解区域。此外，根据历史地位和不同的进入路径，研究发现三种类型的三重解域：“start + LSB + DSBL”、“LSB + SSB + DSBL”和“start + SSB + DSBL”。研究成果不仅极大地丰富了高超声速进气道理论，而且对指导进气道工程实践具有重要意义。